# GMDE Lite > Geological data recording and visualization tool for field professionals and students. (iPhone/iPad app by Richard Allmendinger.) - Source: https://appshunter.io/ios/app/gmde-lite/id1557325241 (this page in markdown: same URL + `.md`) - Developer: [Richard Allmendinger](https://appshunter.io/developer/1194772609) - Category: Education, Utilities - Price: Free - Rating: 5.00/5 from 2 App Store ratings - Age rating: 4+ - Requires: iOS 15.0 · 47 MB - Languages: American English - Released: 2021-04-26 - Data updated: 2026-08-08 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/gmde-lite/id1557325241/reviews.md ## What is GMDE Lite? GMDE Lite has been designed from the ground up with small phone-sized screens in mind although it also works very well on iPads and spectacularly on iPads with an Apple Pencil. We borrow the best from both GMDE Mobile and Stereonet Mobile and present that functionality in a clean, simple, map-centric interface. Data can be exchanged between GMDE Lite and Desktop, and imported from Stereonet Mobile, GIS programs, as well as uploaded or downloaded to/from StraboSpot. Some things GMDE Lite can do: • Set a point of interest (POI) at your current location or anywhere on the map which is immediately tagged with location time and date and to which you can attach a photo and an extended description. You can email a POI, complete with photo, to a field partner, Advisor, etc. • Annotate photos or make digital sketches attached to points of interest. • Enter an orientation by any of six methods: (1) using the device orientation, (2) tapping 3 points on the map and having the device calculate the orientation, (3) sighting along the contact plane either in the strike or dip direction, (4) best fit plane to selected vertices on a path, or (5) type typing in the orientation at the location that you specify. You can project a contact temporarily as a check on the validity of the orientation; the projected contact can be converted to a regular contact. • Read in and display POIs, orientations, and contacts on the map data from Stereonet Mobile or GMDE Desktop. Use copy and paste between devices registered to the same Apple ID using Apple HandOff technology. • Enter contacts by tapping and dragging a path, by recording a GPS track, or by projecting a planar orientation across the landscape. Edit contacts by lassoing and deleting vertices or tapping and dragging individual vertices (works way better on an iPad with Apple Pencil than it does with your finger on a relatively tiny iPhone screen). • Use the device camera/orientation as a rangefinder and plot a point of interest at the sighted location. Rapidly use the rangefinder to determine azimuth, inclination, slope, horizontal, and vertical distance to the sighted location. • Display orientation data on an equal area, lower hemisphere projection which can be filtered by data type. Mean vectors, cylindrical best fits, poles to planes, and rose diagrams can be displayed. • If you have a data connection, GMDE Lite can display your data on Apple Maps within the program as well as get point elevations from an online server. • Use a variety of icons and colors to represent different types of data. • Access all of your data on your device from, and upload to and download from, the Files app on the device. Upload to and download from StraboSpot. Copy and paste between GMDE Lite and Stereonet Mobile. Skills you need to take full advantage of GMDE Lite: GMDE Lite can be used "right out of the box" with a cellular data connection using an online satellite or road base map, and online elevation server, in 2D to measure and collect strikes and dips, plot contacts, do 3-pt problems, etc. To experience the full power of GMDE Lite, and for complete offline operation (essential in remote field areas), you will need to know how to do the following: • Produce base maps from whatever source you want in MBTiles format. Because you are producing your own base maps you can use whatever you want (existing geologic maps, USGS Topo Maps, LiDAR hill shade images, etc.) and not just the few option available from online mapping companies. Maps can be produced with my free desktop program MBTileMakerViewer. • Download and format digital elevation models (DEMs) in GridFloat or BIL format. Having a DEM on the device is what allows GMDE Lite to perform its magic such as calculating an orientation from three points. DEMs can be produced with my free program DEM Masher (requires GDAL). • Know enough about your digital devices to understand how to move files onto or off the device from/to your desktop computer. ## Key features - Record points of interest with photos and descriptions - Annotate photos and create digital sketches - Multiple methods for orientation input - Data import/export from various sources - Visualize orientation data on equal area projection - Use device as a rangefinder for distance calculation ## Frequently asked questions about GMDE Lite ### What is GMDE Lite used for? GMDE Lite is designed for recording and analyzing geological data in the field. It allows users to log points of interest, capture orientations, and map contacts, with features for annotation and data visualization. ### Is GMDE Lite free to use? Yes, GMDE Lite is available for free. The app does not have any in-app purchases or advertisements, making it completely free for users. ### What devices does GMDE Lite support? GMDE Lite is available on iPhone, iPad, and iPod touch devices. It is optimized for small screens but also works well on iPads, especially with an Apple Pencil. ### How does GMDE Lite handle data exchange? Data can be exchanged between GMDE Lite and Desktop versions, imported from Stereonet Mobile, GIS programs, and uploaded/downloaded to StraboSpot. It also supports copy and paste between devices using Apple HandOff. ### Can I use GMDE Lite offline? While GMDE Lite can function with an online base map and elevation server, core data recording and visualization features are available offline. Data exchange and certain online services require a connection. ### What is the age rating for GMDE Lite? GMDE Lite has an age rating of 4+. This indicates it is suitable for a wide range of users, including younger students learning about geology. ### How often is GMDE Lite updated? The latest version of GMDE Lite is 7.2.0, last updated on June 2, 2026. Updates typically include improvements to functionality and compatibility. ### What are the benefits of using an Apple Pencil with GMDE Lite? Using an Apple Pencil with GMDE Lite on an iPad significantly enhances the editing of contacts by allowing for more precise lassoing and dragging of individual vertices compared to using a finger on smaller screens. ## Version history (last 5 releases) ### 8.0.0 — 2026-08-07 v. 8.0.0 -- 6 August 2026 (Finally...) • NEW -- GMDE can now download (when you have an internet connection) and cache permanently on your device map tiles from the USGS and from the Open Topo Map project. The app will automatically store the tiles in an MBTiles database. USGS Topo and Imagery map tiles are only available in the United States but Open Topo Map tiles (with 10 m contours based on the 30 m SRTM DEM) can be downloaded for anywhere in the world. To download map tiles go to the Settings Screen and toggle on "Download Map Tiles". A message box will appear asking you the source you want to use for map tiles. When you tap the source, you will be taken to the Map or the Online Satellite screen. Adjust the view by pinching and dragging until the area for which you want to download tiles fills the screen. I suggest zooming out no more than level 12 to avoid downloading a huge number of tiles all at once (please do not abuse these free sources of map tiles!). Then, tap the name of the data source in the Map Button menu (e.g., for USGS Topo Map tiles tap "USGS Topo Cache") and your download will start automatically. All zoom levels between your starting zoom level (e.g., 12) and zoom level 16 (2 m/pixel, the highest zoom for which USGS tiles are available) will be downloaded to your device. You can pan the map once tiles have been downloaded to start new downloads of adjacent areas. When you are finished downloading, eith tap the "Stop Download" button that appears during downloading, go to the Settings Screen and toggle off "Download Map Tiles" or switch to any other map using the Map Button menu. • NEW -- GMDE Lite will not allow you to zoom in one level higher than the maximum level in your map tiles database. For example, If you have downloaded USGS Imagery Tiles to the maximum of level 16 (2 m/pixel), when viewing those times, you will be able to zoom to level 17 (1 m/pixel). This may help to separate closely spaced measurements. • NEW -- When you export your data as a KMZ file, that file will now include any photos. Thumbnails of the photos will be displayed automatically in Google earth. v. 7.3.0 -- 26 June 2026 • NEW -- All of the toolbar buttons now have popup menus rather than message boxes for making your selection. These menus are faster and more elegant than the previous way of doing things. • NEW -- Pause and resume an activity such as collecting a GPS track or sketching on a map. The functionality has been enabled by the new menu interface: e.g., tap the measure tool and choose Record GPS track from the menu. The toolbar measure button starts flashing. when you need to pause a track, tap the flashing toolbar button. The resulting menu now shows Pause and End. Tap pause. When you're ready to resume tap the toolbar button and the menu will now say Resume and End. Tap resume to continue collecting your track. To end the track, tap the button and choose End from the menu. • NEW -- From the Add Orientation menu (accessed from the Orientation button on the toolbar), you can now go directly to collecting and orientation by Device Orientation (when you want to put your phone on the plane to be measured) or directly to the sighting an orientation screen. When you go to the sighting screen, as soon as you tap the display when there is a valid measurement the screen will close and you will see the orientation in the Orientation Details screen. Both device orientation and sighting were, and still are, available from buttons in the toolbar for the Orientation Details screen. The just gives you a little fast way of collecting those measurements. • NEW -- You can now enter an orientation in the orientation details screen by tapping and dragging in the stereonet at the bottom of the screen. • NEW -- The Rangefinder can now be used to measure the azimuth and inclination by sighting through your device camera. ### 7.3.0 — 2026-06-27 v. 7.3.0 -- 26 June 2026 • NEW -- All of the toolbar buttons now have popup menus rather than message boxes for making your selection. These menus are faster and more elegant than the previous way of doing things. • NEW -- Pause and resume an activity such as collecting a GPS track or sketching on a map. The functionality has been enabled by the new menu interface: e.g., tap the measure tool and choose Record GPS track from the menu. The toolbar measure button starts flashing. when you need to pause a track, tap the flashing toolbar button. The resulting menu now shows Pause and End. Tap pause. When you're ready to resume tap the toolbar button and the menu will now say Resume and End. Tap resume to continue collecting your track. To end the track, tap the button and choose End from the menu. • NEW -- From the Add Orientation menu (accessed from the Orientation button on the toolbar), you can now go directly to collecting and orientation by Device Orientation (when you want to put your phone on the plane to be measured) or directly to the sighting an orientation screen. When you go to the sighting screen, as soon as you tap the display when there is a valid measurement the screen will close and you will see the orientation in the Orientation Details screen. Both device orientation and sighting were, and still are, available from buttons in the toolbar for the Orientation Details screen. The just gives you a little fast way of collecting those measurements. • NEW -- You can now enter an orientation in the orientation details screen by tapping and dragging in the stereonet at the bottom of the screen. • NEW -- The Rangefinder can now be used to measure the azimuth and inclination by sighting through your device camera. v. 7.2.0 -- 2 June 2026 • NEW -- The rangefinder now has an option to measure vertical angles only. If you know your horizontal distance to the outcrop, the app can calculate thickness of horizontal units in a cliff face (or measure the height of a treen, etc.). Just set the lower angle to the base of the unit and the upper angle to the top of the unit. There are lots of other potential uses for this function. • NEW -- When measuring a strike and dip with the device orientation, a green line will appear from topo to bottom on the stereonet face when the long axis of the phone is horizontal. An arrowhead on one end of the line shows the physical direction of the given strike direction. Explanation: Because the app measured the pole to the plane directly, you can place the phone on the bedding surface in any orientation. But, sometimes, you want to know where the strike line is (e.g., when collecting and marking an oriented sample). This allows you to find the actually strike line in the plane as well as determine which direction you should mark the sample so that it coincides with the measured strike line. • FIXED -- Switching between base maps now works more smoothly without showing a blank white screen. v. 7.1.0 -- 11 May 2026 • NEW -- Subsampling and smoothing contacts are now undoable. • NEW -- Additional database integrity checks are now in place. The checks are carried out every time you open a database. If corruption is found, the problematic rows are reported. • NEW -- If the app experiences a hard crash (with no error message), the next time you start up the app, it will warn you of an abnormal exit and will inform you that it is starting up without opening up the last database used (just in case). V.7.0.2 -- 13 April 2026 • NEW -- Correction for camera bump on the back of modern phones. ### 7.2.0 — 2026-06-02 v. 7.2.0 -- 2 June 2026 • NEW -- The rangefinder now has an option to measure vertical angles only. If you know your horizontal distance to the outcrop, the app can calculate thickness of horizontal units in a cliff face (or measure the height of a treen, etc.). Just set the lower angle to the base of the unit and the upper angle to the top of the unit. There are lots of other potential uses for this function. • NEW -- When measuring a strike and dip with the device orientation, a green line will appear from topo to bottom on the stereonet face when the long axis of the phone is horizontal. An arrowhead on one end of the line shows the physical direction of the given strike direction. Explanation: Because the app measured the pole to the plane directly, you can place the phone on the bedding surface in any orientation. But, sometimes, you want to know where the strike line is (e.g., when collecting and marking an oriented sample). This allows you to find the actually strike line in the plane as well as determine which direction you should mark the sample so that it coincides with the measured strike line. • FIXED -- Switching between base maps now works more smoothly without showing a blank white screen. v. 7.1.0 -- 11 May 2026 • NEW -- Subsampling and smoothing contacts are now undoable. Just give your device a shake within 2 minutes of applying the subsampling or smoothing, and the old contact will be restored. Subsampling now uses the Ramer-Douglas-Peucker (RDP) algorithm for better results. The degree of subsampling can now be set with a slider control. As you move the slider, the number of vertices to be deleted will appear above the slider. • NEW -- Additional database integrity checks are now in place. The checks are carried out every time you open a database. If corruption is found, the problematic rows are reported. • NEW -- If the app experiences a hard crash (with no error message), the next time you start up the app, it will warn you of an abnormal exit and will inform you that it is starting up without opening up the last database used (just in case). You’ll need to open the database by going to the settings screen and tapping Open Project. With the new database integrity check, if the DB causes the problem, you will be informed when you try to open it. If the problem is with the tiny resume file, that will be rewritten when you open the database. This way, the app will remain operable, and you can troubleshoot the problem more effectively rather than continuing to crash repeatedly with no message and no recourse. V.7.0.2 -- 13 April 2026 • NEW -- Correction for camera bump on the back of modern phones. Modern iPhones and iPads have bumps or plateaus on the back to accommodate more powerful cameras, and rugged cases can make the back of the phone even more irregular. This means the back is no longer flat, which can impact measuring of strikes and dips by placing the device on the bedding or fault surface. This version can correct for that non-planarity: Go to the Settings Screen (gear icon) and tap the new option "Correction for Camera bump." You will be taken to a new screen entitled Camera Bump Correction. Follow the instructions on the screen to set the correction factors. You can also use this screen to reset the correction factors to zero. Once set, these corrections will be applied whenever you measure the orientation by placing your device on the outcrop and will remain active even when you change projects. An incorrectly applied correction (e.g., not following the instructions) can thoroughly mess up your measurements!! You'll see from the displayed pitch and roll angles that the corrections are typically small, but more accurate is always better! • IMPROVED -- Outline text has been made more legible by a slight increase in the spacing between letters. • FIXED -- A bug that prevented the reading of some newly saved newly saved contact type characteristics. Other bugs fixed as well. ### 7.1.0 — 2026-05-12 v. 7.1.0 -- 11 May 2026 • NEW -- Subsampling and smoothing contacts are now undoable. Just give your device a shake within 2 minutes of applying the subsampling or smoothing, and the old contact will be restored. Subsampling now uses the Ramer-Douglas-Peucker (RDP) algorithm for better results. The degree of subsampling can now be set with a slider control. As you move the slider, the number of vertices to be deleted will appear above the slider. • NEW -- Additional database integrity checks are now in place. The checks are carried out every time you open a database. If corruption is found, the problematic rows are reported. • NEW -- If the app experiences a hard crash (with no error message), the next time you start up the app, it will warn you of an abnormal exit and will inform you that it is starting up without opening up the last database used (just in case). You’ll need to open the database by going to the settings screen and tapping Open Project. With the new database integrity check, if the DB causes the problem, you will be informed when you try to open it. If the problem is with the tiny resume file, that will be rewritten when you open the database. This way, the app will remain operable, and you can troubleshoot the problem more effectively rather than continuing to crash repeatedly with no message and no recourse. V.7.0.2 -- 13 April 2026 • NEW -- Correction for camera bump on the back of modern phones. Modern iPhones and iPads have bumps or plateaus on the back to accommodate more powerful cameras, and rugged cases can make the back of the phone even more irregular. This means the back is no longer flat, which can impact measuring of strikes and dips by placing the device on the bedding or fault surface. This version can correct for that non-planarity: Go to the Settings Screen (gear icon) and tap the new option "Correction for Camera bump." You will be taken to a new screen entitled Camera Bump Correction. Follow the instructions on the screen to set the correction factors. You can also use this screen to reset the correction factors to zero. Once set, these corrections will be applied whenever you measure the orientation by placing your device on the outcrop and will remain active even when you change projects. An incorrectly applied correction (e.g., not following the instructions) can thoroughly mess up your measurements!! You'll see from the displayed pitch and roll angles that the corrections are typically small, but more accurate is always better! • IMPROVED -- Outline text has been made more legible by a slight increase in the spacing between letters. • FIXED -- A bug that prevented the reading of some newly saved newly saved contact type characteristics. Other bugs fixed as well. ### 7.0.2 — 2026-04-14 V.7.0.2 -- 13 April 2026 • NEW -- Correction for camera bump on the back of modern phones. Modern iPhones and iPads have bumps or plateaus on the back to accommodate more powerful cameras, and rugged cases can make the back of the phone even more irregular. This means the back is no longer flat, which can impact measuring of strikes and dips by placing the device on the bedding or fault surface. This version can correct for that non-planarity: Go to the Settings Screen (gear icon) and tap the new option "Correction for Camera bump." You will be taken to a new screen entitled Camera Bump Correction. Follow the instructions on the screen to set the correction factors. You can also use this screen to reset the correction factors to zero. Once set, these corrections will be applied whenever you measure the orientation by placing your device on the outcrop and will remain active even when you change projects. An incorrectly applied correction (e.g., not following the instructions) can thoroughly mess up your measurements!! You'll see from the displayed pitch and roll angles that the corrections are typically small, but more accurate is always better! • IMPROVED -- Outline text has been made more legible by a slight increase in the spacing between letters. • FIXED -- A bug that prevented the reading of some newly saved newly saved contact type characteristics. Other bugs fixed as well. V. 7.0.1 --24 March 2026 • FIXED -- A bug that would cause crashing immediately after install of v. 7.0.0 in some unusual circumstances. • FIXED -- A bug that would cause the map overlay transparency slider on the Map Screen to disappear when it was set to 100% transparency and the user temporarily left the Map Screen (e.g., when entering an orientation or POI. The slide will now be there when you go back to the Map Screen. v. 7.0.0 -- 21 March 2026 • NEW -- Calculate the slip magnitude on a fault given the orientation of the slip vector (from slickensides, mylonitic lineations, etc.) and any two points on a planar contact that has been offset by the fault. For the calculation to be accurate, it requires that the offset plane have the same orientation on either side of the fault. To do this calculation, first measure the lineation on the fault plane. Tap the lineation and then select "Displ. from Separation". You will then need to type in the orientation of the offset plane. Then tap on the contact on the map on one side of the fault, and then again on the same contact on the other side of the fault. As you tap and drag along the 2nd contact, the slip is displayed next to the pointer hotpoint. When you lift the pointer, the slip will be displayed in a message box and it will also be written to the notes field of the lineation on the fault plane. Interestingly enough, entering the strike and dip of the fault plane is not necessary for this calculation! Also, the intersection of the fault plane with the contact does not need to be exposed anywhere. NEW -- You can now specify the font size by observation type so, for example, the labels for fossil sample POIs can be a different size than formation type POIs, etc. The same is true for orientation and contact types. You set the font size by going to the Settings Screen (gear icon), tap Edit Data Types & Tags, select the POI, Orientation, or Contact type to Edit, then tap the Edit button and in the Edit Type screen, enter the Font Size. Following the same path, you can use the switch next to the Font Size label to toggle on or off whether labels are shown on the map for that type. Thus, you can opt to show contact names for stratigraphic type contacts but not for, say, access roads. FIXED -- A few more, mostly minor bugs were squashed. ## Apps similar to GMDE Lite | App | Rating | Price | Category | | --- | --- | --- | --- | | [Mancos](https://appshunter.io/ios/app/mancos/id541570878) | 5.0 (13) | $2.99 | Education | | [ICS-Timescale](https://appshunter.io/ios/app/ics-timescale/id1469322356) | 4.3 (3) | Free | Education | | [DeepTime for Geology](https://appshunter.io/ios/app/deeptime-for-geology/id1500200416) | 5.0 (7) | Free | Education | | [Nomad Geologist](https://appshunter.io/ios/app/nomad-geologist/id1462577133) | 5.0 (6) | Free | Education | | [StraboTools](https://appshunter.io/ios/app/strabotools/id1496239162) | 5.0 (10) | Free | Education | | [Geology Dictionary - Offline](https://appshunter.io/ios/app/geology-dictionary-offline/id1488197434) | 3.4 (5) | Free | Education | ## More apps by Richard Allmendinger - [Stereonet Mobile](https://appshunter.io/ios/app/stereonet-mobile/id1194772610) - [FaultKin Mobile](https://appshunter.io/ios/app/faultkin-mobile/id1234264776) - [Strat Mobile](https://appshunter.io/ios/app/strat-mobile/id1289101464) - [Chocorua Map](https://appshunter.io/ios/app/chocorua-map/id1475276985) - [White Mtn Hiker Pemi](https://appshunter.io/ios/app/white-mtn-hiker-pemi/id1580650866) All apps by Richard Allmendinger: https://appshunter.io/developer/1194772609 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-08.*