Comparison

Theodolite vs Eos Tools Pro

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Theodolite

This app combines a compass, inclinometer, rangefinder, GPS, and map with augmented reality features. Capture photos and videos with overlaid geographical data, and navigate using detailed offline maps. Share locations and collaborate with others for various outdoor and professional uses.

Highlights
  • Augmented reality viewfinder
  • Compass and inclinometer
  • GPS and map navigation
  • Data-overlay photo/video camera
  • Offline map support
  • Rangefinder and nav calculator
  • Coordinate system support
Currently charting
Read full description

Theodolite is a multi-function viewfinder that combines a compass, two-axis inclinometer, rangefinder, GPS, map, nav calculator, and geo-overlay photo/movie camera into one indispensable app. Theodolite was one of the very first augmented reality (AR) apps when it was released in 2009, and it’s been downloaded and used by millions of customers since then. Uses are endless, and the app is great for land measurements, outdoor sports, sightseeing, navigation, and finding your way around. Theodolite is a pro grade app and is used extensively by surveyors, geologists, architects, engineers, competitive sportsmen, first responders, military personnel, and search and rescue workers around the world. Theodolite lets you take data-overlay photos and movies with 2X-8X zoom. Overlay geographical data, angle markings, date/time, author/company info, and project notes directly on photos and movies for later reference. The same data is written into the metadata record of images, making image files self-contained data records. Third-party apps can tap into Theodolite's advanced camera functions with a camera sharing feature. View current position on the built-in map with optional offline Outdoors maps that include topo contours, roads, trails, landmarks, campgrounds, ski lifts, and more. Live map markers continually update distance/heading relative to the current location and also show wayfinding info in the main viewfinder. Draw polygons on the map to mark things like property boundaries and trails, and import/export polygon data via KML. Share map markers and nav calculator points with other users of Theodolite via text messages or e-mail. This powerful capability opens up a wide range of collaborative uses including team land surveying, accident investigations, spotting wild fires, triangulation of landmarks, and advanced tactical observation and targeting. With an optional in-app purchase to enable team tracking, you can share location with up to 20 people on Theodolite's map. Theodolite includes features for serious users like a reference angle mode, nav calculator, map marker import/export, manual and automatic data logging with CSV and KML export, clipboard integration, %grade display, mil compass readout, optical rangefinders (including a mil-based reticle, sniper-style stadiametric graphs, and a variable 4X-24X scope), and night filters to improve use in dark conditions. Theodolite can provide location in military grid reference system (MGRS) coordinates, Universal Transverse Mercator (UTM) coordinates, British/Irish National Grids, US National Grid, Maidenhead locator system, Map Grid of Australia, and six latitude/longitude formats. Optional US State Plane coordinates include SPCS27 and SPCS83 zones covering all US States. The optional Datum Pack adds over 230 geodetic datums to the app to improve position computation from GPS data, covering regions and countries on all continents around the world. AR Layers include navigational aids like the sun, moon, planets, and Polaris (North star), and the optional US Mountain Summits layer that shows over 70,000 US mountain summits in the viewfinder. Theodolite has been shown in Apple Keynotes, featured on the App Store, and has been a #1 selling Navigation app in App Stores around the world. Since its introduction in 2009, Theodolite has defined augmented reality navigation. The app continually introduces new technologies, pushing the limits of iOS app development and taking advantage of new hardware capabilities. Find out why Apple named Theodolite one of the most amazing apps available and showed it being used to explore the Great Wall of China. Where will you take it on your next adventure? Note: Theodolite is an iPhone app -- see “Theodolite HD” for use on an iPad. And be sure to check out the all-new "Theodolite for Watch" and put Theodolite on your wrist!

About

Eos Tools Pro

This utility app provides advanced GNSS information for high-precision receivers, crucial for GIS and surveying. It includes an NTRIP client for corrections, user-configurable alarms, and background operation with mapping software.

Highlights
  • Advanced GNSS information (RMS, PDOP, differential status)
  • Built-in NTRIP client for RTK/DGNSS corrections
  • User-configurable audible alarms
  • Background operation with mapping software
  • Satellite view for multiple constellations
  • Orthometric Height and Position Shift computation
Features
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Eos Tools Pro is a monitoring utility for the Arrow and Skadi series high precision GNSS receivers from Eos Positioning Systems. It provides advanced GNSS information such as RMS values, PDOP, differential status, satellites tracked and used, that are critical for submeter and centimeter GIS and surveying data collection. The app features a built-in end trip client to access RTK or DGNSS corrections from an RTK network. Eos Tools Pro also allows audible user configurable alarms and runs in the background of your mapping surveying software. Features: - Built-in NTRIP client to connect to an RTK Network - Displays GNSS and Tilt Compensation accuracy with quality control information - Select the Skadi Smart Handle mode: Extensible Virtual Range Pole™ or Invisible Range Pole™ - Satellite view for all constellations in use (GPS, GLONASS, BeiDou, QZSS and IRNSS) - User configurable alarms - Orthometric Height (Geoid models for vertical datum) - Compute and apply Position Shifts to accommodate different - Laser Offset Mapping for Esri ArcGIS® Field Maps - Locate and map underground utility assets directly in ArcGIS Field Maps - Terminal emulator to send configuration commands to the receiver - HTML5 built-in browser Disclaimer: "Continued use of Eos Tools Pro running in the background and connected to the GPS/GNSS receiver can dramatically decrease the battery life of your Apple device." Technical Support: For technical support, questions, feedback or bug reporting, please contact support@eos-gnss.com.

Screenshots

Theodolite4 screens
Eos Tools Pro4 screens

Verdict

The call

Theodolite and Eos Tools Pro both sit at 4.7 stars, but that hides the real split: 88% of Theodolite's written reviews are positive against 38% of Eos Tools Pro's. Theodolite also leads on ratings volume (902 vs 9) and chart position (#7 vs unranked). Eos Tools Pro's advantage is price (Free vs $8.99) and in-app purchases (none vs 8). On rating, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Eos Tools Pro is free to download; Theodolite costs $8.99 up front. Theodolite sells 8 one-off in-app purchases. Eos Tools Pro asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for Theodolite against 4.6 for Eos Tools Pro. That said, the two scores are not equally well evidenced: Theodolite has 902 ratings behind it against 9, so its average is the more settled of the two. Written reviews are what separate them: 88% of Theodolite's written reviews are positive against 38% of Eos Tools Pro's.

UpkeepUpdate frequency

Theodolite ships an update every 4 months, Eos Tools Pro every 2 months. The most recent releases landed on September 24, 2026 and September 18, 2026 respectively.

Scorecard8 real differences · 3 level
Theodolite versus Eos Tools Pro: the parameters behind the verdict, then further details
ParameterTheodoliteEos Tools Pro
Price$8.99Free — better
Rating4.7 (902 ratings) — better4.6 (9 ratings)
Positive reviews87.8% of reviews — better37.5% of reviews
Number of ratings902 — better9
Update frequencyEvery 4 monthsEvery 2 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
Best chart rank#7 — better—
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.6 — better17.0
Further details — not scored
Size30 MB36 MB
Age rating4+17+
DeveloperCraig HunterEos Positioning Systems

Customer experience

Theodolite

All ratings902 ratings
Positive92.8%
Neutral2.9%
Negative4.3%
Written reviews475 reviews
Positive87.8%
Neutral4.8%
Negative7.4%

Eos Tools Pro

All ratings9 ratings
Positive88.9%
Neutral11.1%
Negative0.0%
Written reviews8 reviews
Positive37.5%
Neutral12.5%
Negative50.0%

In-app purchases

8 purchases

Theodolite

One-time8
  • 1,000 Outdoors Map Tiles$0.99
  • Team Tracking$1.99
  • World Datum Pack$2.99
Show 5 more
  • US Mountain Summits AR Layer$2.99
  • 5,000 Outdoors Map Tiles$4.99
  • 10,000 Outdoors Map Tiles$8.99
  • 20,000 Outdoors Map Tiles$17.99
  • US State Plane Coordinates$24.99
None

Eos Tools Pro

No in-app purchases

Questions

Is Theodolite free?
Theodolite costs $8.99, and also offers in-app purchases.
Is Eos Tools Pro free?
Eos Tools Pro is free to download, with no in-app purchases.
Which has better reviews, Theodolite or Eos Tools Pro?
Theodolite is rated higher. Theodolite averages 4.7 out of 5 from 902 ratings, while Eos Tools Pro averages 4.6 from 9 ratings.
Do Theodolite or Eos Tools Pro have ads?
Neither Theodolite nor Eos Tools Pro shows ads.
Which is updated more often, Theodolite or Eos Tools Pro?
Theodolite ships an update every 4 months, and Eos Tools Pro every 2 months. Most recently, Theodolite was updated on September 24, 2026 and Eos Tools Pro on September 18, 2026.

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