# Foil Sessions - Prone Foiling app for Apple Watch (and iPhone) **URL:** \ **Category:** Prone Surf Foiling\ **Created:** [January 13, 2025, 7:02am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287 "2025-01-13T07:02:53Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [January 13, 2025, 7:02am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/1 "2025-01-13T07:02:53Z")
I’ve been developing a foiling app for the Apple Watch for a while now, and it’s getting close to completion. The app features recording modes for wing foiling, dock starts, and prone surfing (downwind coming soon). Since there aren’t any good prone surf spots where I live (and I suck at it), fine-tuning the algorithm for prone surfing has been pretty challenging. If you’re interested in testing the app or have suggestions for features you feel are missing from the apps you currently use, feel free to send me a DM!” [![](https://canada1.discourse-cdn.com/flex030/uploads/progressionproject/original/2X/a/a86d00053b82bd9a65d132c7180a6f2aedf127d0.jpeg "Foil Sessions App for Apple Watch") ](https://www.youtube.com/watch?v=TMXEDzJxebQ) ![Screenshot 2025-01-12 at 22.02.22](https://canada1.discourse-cdn.com/flex030/uploads/progressionproject/original/2X/b/bc099ea175f24f6c52bd9b71662639376e771044.jpeg) ---
**Author:** ![Gneve](https://avatars.discourse-cdn.com/v4/letter/g/c77e96/32.png) [@Gneve](https://forum.progressionproject.com/u/Gneve)\ **Post date:** [January 13, 2025, 1:46pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/2 "2025-01-13T13:46:55Z")
I’m interested to hear how your app deciphers wave start and wave end. I’ve been using dawn patrol and the weakest part of that app is the accuracy in terms of start/stop. ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [January 13, 2025, 2:19pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/3 "2025-01-13T14:19:43Z")
At the start of a session, you set the direction of the waves, which is then used for the calculations. It’s been quite accurate so far, but I could use some help validating and fine-tuning the algorithm. Think of it as an opportunity to get an app tailored to your riding style. ---
**Author:** ![Gneve](https://avatars.discourse-cdn.com/v4/letter/g/c77e96/32.png) [@Gneve](https://forum.progressionproject.com/u/Gneve)\ **Post date:** [January 13, 2025, 4:51pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/4 "2025-01-13T16:51:00Z")
Do you run testing through TestFlight? ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [January 13, 2025, 5:08pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/5 "2025-01-13T17:08:03Z")
Yes, send me a dm if you’re interested in testing. 👍 ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [January 22, 2025, 3:26pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/6 "2025-01-22T15:26:56Z")
The dock start algorithm and user interface are now ready for real-life testing. If you’re dock starting, I’d be super happy if you could give it a try. ![Screenshot 2025-01-22 at 07.55.49](https://canada1.discourse-cdn.com/flex030/uploads/progressionproject/original/2X/7/7dbed8b1a95771f420fe365ca7232eb21e4a6063.jpeg) ---
**Author:** ![FoilWays](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/foilways/32/5224_2.png) [@FoilWays](https://forum.progressionproject.com/u/FoilWays)\ **Post date:** [January 22, 2025, 6:50pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/7 "2025-01-22T18:50:28Z")
Interested. I’ve been using the Waterspeed app, but it’s better for winging. Yeah, I’ll use it for surfing and for prone, but it doesn’t track wave count. ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [January 22, 2025, 9:20pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/8 "2025-01-22T21:20:56Z")
I recently received this prone foil session from a tester in Waikiki. Do you think any data might be missing for prone foiling? If you’d like to test it yourself, feel free to DM me your email, and I’ll send you a TestFlight invite. [![](https://canada1.discourse-cdn.com/flex030/uploads/progressionproject/original/2X/e/e0d0043ac29b354f41182bdb02e350b262b2ca57.jpeg "Prone foil session Waikiki") ](https://www.youtube.com/watch?v=NrlGsnpOafA) ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [February 3, 2025, 10:33am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/9 "2025-02-03T10:33:24Z")
Development is progressing nicely. Here are some of the current screens on the Apple Watch. ![watch-app](https://canada1.discourse-cdn.com/flex030/uploads/progressionproject/original/2X/1/1c422d87367c302f2fa7116bcb5c69c798fa0963.jpeg) ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [February 14, 2025, 8:41am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/10 "2025-02-14T08:41:39Z")
Track coloring has gotten a huge overhaul in recent days. What do you think? [![](https://canada1.discourse-cdn.com/flex030/uploads/progressionproject/original/2X/f/fda005b82de9881bee445ea3bbb6df0f50426b09.jpeg "Foil Sessions Quick Tutorial") ](https://www.youtube.com/watch?v=WPK_36hIoR4) ---
**Author:** ![Matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@Matt](https://forum.progressionproject.com/u/Matt)\ **Post date:** [February 14, 2025, 11:13am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/11 "2025-02-14T11:13:24Z")
maybe too niche, but I wonder about tacking angles and the VMG. Do you think there is a way to make an approximate VMG? Would be useful for the parawing/wing efficiency convo ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [February 15, 2025, 8:01am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/12 "2025-02-15T08:01:30Z")
The watch app will retrieve the current wind direction from the nearest weather buoy or station when you start a new session. If this data is unavailable or inaccurate, you can set it manually. This could be used to calculate VMG, but as soon as the wind direction changes, the calculations would become slightly off. The math is straightforward, so implementation should be quick—if there’s interest, I could do a test run. For the iPhone app, one possible feature could be a tool that lets you mark two upwind legs. The app would then calculate the angle between them and determine the VMG achieved during those tacks. This method would be extremely accurate and might better align with what you’re looking for. What do you think? ---
**Author:** ![Matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@Matt](https://forum.progressionproject.com/u/Matt)\ **Post date:** [February 17, 2025, 8:26am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/13 "2025-02-17T08:26:56Z")
Yes I think setting wind direction or upwind manually and approximately would be best. I am not winging so wouldn’t be able to test it. Maybe more useful would be a quick GPS track upload feature that shows the relative tacking angles, and checks which have the smallest angle between them, meaning better upwind? ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [March 27, 2025, 4:18pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/14 "2025-03-27T16:18:40Z")
The app is finally live on the App Store! Still on the lookout for testers though — so if you’re keen to make sure it picks up your style of riding, drop me a DM. > **[‎Foil Sessions](https://apps.apple.com/se/app/foil-sessions/id6479241056)** > > ‎Foil Sessions has been developed by a foiler together with the foiling community. It provides on-water metrics tailored to your specific foiling passions—whether it’s wing foiling, prone foiling, dock start, beach start, downwind runs, tow boogie,... ---
**Author:** ![FoilFondler](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/foilfondler/32/299_2.png) [@FoilFondler](https://forum.progressionproject.com/u/FoilFondler)\ **Post date:** [March 27, 2025, 10:24pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/15 "2025-03-27T22:24:31Z")
Is there a way to connect with a foil drive to eliminate “waves” when the motor is running? ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [March 29, 2025, 1:51pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/16 "2025-03-29T13:51:27Z")
No way to connect to a Foil Drive at the moment. It might be possible in the future, but unless they get a flood of customer requests, they’ve got no reason (and rightly so) to spend their limited resources on it. (Unless, of course, their remote already exposes a BLE interface—but I haven’t found any sign of that on the internet.) At the moment, there’s also no wave-power-assisted recording mode in the app—but I think there should be. The problem is, it won’t be very accurate unless we know whether the motor is actually running or not. We could assume you’re under power if you’re moving against the wave direction for a certain number of seconds, but there’s no reliable way to tell the difference between riding a wave and powered riding with the waves. Still, maybe a rough estimate is better than nothing? ---
**Author:** ![FoilFondler](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/foilfondler/32/299_2.png) [@FoilFondler](https://forum.progressionproject.com/u/FoilFondler)\ **Post date:** [March 29, 2025, 3:50pm UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/17 "2025-03-29T15:50:50Z")
Maybe use the microphone as a wet fart detector? But then a bad meal can throw off your stats. ---
**Author:** ![jenz](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.progressionproject.com/jenz/32/16455_2.png) [@jenz](https://forum.progressionproject.com/u/jenz)\ **Post date:** [March 30, 2025, 8:50am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/18 "2025-03-30T08:50:06Z")
Haha, I actually thought of using the mic but it was not the meal induced wet fart scenario that made me drop it. 😂 ---
**Author:** ![chrispewkreme](https://avatars.discourse-cdn.com/v4/letter/c/0ea827/32.png) [@chrispewkreme](https://forum.progressionproject.com/u/chrispewkreme)\ **Post date:** [April 1, 2025, 12:31am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/19 "2025-04-01T00:31:24Z")
I prone surf nearly every day as there’s always waves. I’d love to help if still needed. I use a Garmin for surf and it fails pretty bad. Some days it tracks perfect. Some days it must think i rode a wave and then paddled back out REALLLY fast and doesn’t track. I put my watch into “BOAT” mode to get a more realistic picture but it doesn’t count waves or speed for each wave. ALL valuable info when comparing waves and foil setups. ---
**Author:** ![chrispewkreme](https://avatars.discourse-cdn.com/v4/letter/c/0ea827/32.png) [@chrispewkreme](https://forum.progressionproject.com/u/chrispewkreme)\ **Post date:** [April 1, 2025, 12:31am UTC](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287/20 "2025-04-01T00:31:56Z")
Awesome to see! I’ll give it a shot and let you know how it goes. [Next page](https://forum.progressionproject.com/t/foil-sessions-prone-foiling-app-for-apple-watch-and-iphone/8287.md?page=2)