qtVlm vs SailTimer API™
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
qtVlm
This navigation software is designed for sailing boats, offering a free version with basic GRIB viewing and an optional full version with advanced weather routing, chart modules, and communication features. It supports various chart formats and NMEA data sources, with a simulation mode for learning.
- GRIB viewer with advanced functions
- Weather routing and route modules
- Support for Raster, Vector, and MBTiles charts
- Harmonic file support for tides and currents
- AIS and Iridium GO! communication
- Anchor Alarm module
- Simulation Mode for learning
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qtVlm is a navigation software for Sailing Boats. The application has a free version with basic features and a full version available through in-app purchase. The free version of qtVlm is a full grib viewer displaying all types of gribs and providing many advanced grib functions. It supports basics charts and some simple instruments. It includes also an Anchor Alarm module, a viewer for shapefiles, for instance those coming from SHOM, and can be configured to receive boat position either from internal GPS or from an external NMEA source connected through tcp, udp or gpsd. The full version adds many functions and features: - Weather routing and route modules, - A complete set of navigation Instruments, - Charts modules for Raster charts, Vector charts (S57, S63 and CM93) and mbtiles, - Support for Harmonic files (tides and currents), - Iridium GO! communication - AIS, - Start line mode, - Access to Great Circle gribs, qtVlm can also be used in Simulation Mode, which allows you to simulate a navigation through our server. This is the best way to learn using qtVlm. Once activated the full version will be available on all your iOS devices.
SailTimer API™
This app bridges the gap between your SailTimer Wind Instrument and other navigation or performance apps. It also offers access to crowdsourced wind maps and marine weather animations through a subscription, enhancing your sailing experience with real-time wind data.
- Integrates with SailTimer Wind Instrument
- Delivers wind data to partner apps
- Crowdsourced wind maps
- Marine weather animations
- Supports chartplotter apps
- Real-time wind data
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This app allows you to use SailTimer products in other partner apps. First, if you have the wireless SailTimer Wind Instrument (www.SailTimerWind.com), this app can receive the transmissions and deliver them to other apps for viewing. Use this app with the the SailTimer™ chartplotter app, or with lots of other navigation, wind gauge or performance apps (https://wi-rb.com/apps/). But what if you want to see what the wind is doing up ahead, or around the next point? Then you need our crowdsourced wind maps and marine weather animations. You can get the low-cost subscription here, to view our marine weather animations in partner apps. We'll add a growing list of partner apps at https://SailTimer.boats App web page: https://wi-rb.com/api. If you have a question or feedback please email info@SailTimer.co - we’re here to help. If you are getting the app and like this wireless technology, please help out other sailors by letting them know with a quick rating on this version while you’re here.
Screenshots
Verdict
The clearest difference is review sentiment: qtVlm at 79% against SailTimer API™'s 0%. qtVlm also leads on update cadence (weekly vs every 4 weeks) and ratings volume (8 vs 1). SailTimer API™'s advantage is rating (5.0 vs 3.5). On price, ads, in-app purchases and monetization model 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
Both are free to download. qtVlm sells 1 one-off in-app purchase and SailTimer API™ sells 6 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.
SailTimer API™ holds the better App Store score, 5.0 against 3.5. That said, the two scores are not equally well evidenced: qtVlm has 8 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 79% of qtVlm's written reviews are positive against 0% of SailTimer API™'s, so the app with the better star average is not the one people write more warmly about.
qtVlm ships an update weekly, SailTimer API™ every 4 weeks. The most recent releases landed on October 14, 2026 and October 1, 2026 respectively.
| Parameter | qtVlm | SailTimer API™ |
|---|---|---|
| Price | Free | Free |
| Rating | 3.5 (8 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 79.2% of reviews — better | 0.0% of reviews |
| Number of ratings | 8 — better | 1 |
| Update frequency | Weekly — better | Every 4 weeks |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.0 — better | 16.6 |
| Further details — not scored | ||
| Size | 100 MB | 19 MB |
| Age rating | 4+ | 4+ |
| Developer | Meltemus SAS | SailTimer Inc. |
Customer experience
qtVlm
SailTimer API™
In-app purchases
qtVlm
- Full version$49.99
SailTimer API™
- Crowdsourced Wind Maps - Monthly7 Days trial$2.991 Month
- WNI Marine Weather - Monthly7 Days trial$2.991 Month
- AI Forecasts - Monthly7 Days trial$2.991 Month
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- Crowdsourced Wind Maps - Yearly7 Days trial$19.991 Year
- WNI Marine Weather - Yearly7 Days trial$19.991 Year
- AI Forecasts - Yearly7 Days trial$19.991 Year
