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Ischys compared with Hevy, Strong and open-source trackers
Checked: 13 October 2026 · open-source section 20 October 2026 · By vplsdev, the developer
The short version: all three log sets, reps and rest timers. Ischys differs in three ways. It is free with no paid tier, it is open source, and your training log stays on your phone, with no Ischys server holding a copy.
Every statement about Hevy and Strong below comes from that company's own website, help centre or App Store listing, linked in the sources. Prices are the United States App Store prices in US dollars and vary by region. If you are choosing between them, read their pages too.
| Ischys | Hevy | Strong | |
|---|---|---|---|
| Price | Free. There is no paid tier. | Free version. Hevy Pro is listed at $2.99 or $3.99 a month, $23.99 a year or $74.99 for lifetime.[1] | Free version. Strong PRO is $4.99 a month or $29.99 a year; the listing also shows a one-time "Strong PRO Forever" purchase at $79.99 and at $99.99.[8] |
| Limits on the free version | None. | 4 routines, 7 custom exercises and 3 months of statistics history. Body measurements other than weight and waist need Pro.[2][5] | 3 custom routines; unlimited workouts can be saved.[8] Access to all charts, the plate calculator, the warm-up calculator and body-part measurements are listed as PRO features.[9] |
| Where your workouts are stored | On your phone. Ischys has no server. | On Hevy's servers.[3] | On Strong's servers, in the United States and other countries.[10][11] |
| Account | None. | Workouts are saved to your Hevy profile.[3] | Users are prompted to sign up before using the app.[10] |
| Source code | Open source under the MIT licence, on GitHub. | Proprietary: the terms grant only a "limited, non-exclusive, nontransferable license" to use the app.[4] | Proprietary: the terms call the service "the exclusive property of Strong Fitness PTE. Ltd. and its licensors".[12] |
| Platforms | iPhone and Apple Watch. Android is in closed testing on Google Play; the Wear OS app is awaiting Google's review. Neither is public yet. | iPhone, iPad, Android, web browser, Apple Watch and Wear OS.[1][5] | iPhone, Android and Apple Watch.[13] |
| Lock Screen Live Activity | Yes. | Yes.[1] | Yes, for rest timers.[8] |
| Apple Health | Yes. | Yes.[1] | Yes.[14] |
| Export | CSV and JSON. | CSV.[6] | CSV.[15] |
| Import | A workout CSV, or an Ischys JSON export. | CSV files exported from Strong.[7] | Exported files cannot be imported back.[15] |
| Ads | None. | None.[1] | None.[16] |
Where Hevy and Strong are ahead
- Android today. Both have public Android apps.[5][13] Ischys for Android is still in closed testing.
- More platforms. Hevy also runs in a web browser, on iPad and on Wear OS.[1][5]
- History that follows your account. Because both keep your workouts on their servers, your log is there when you sign in on a new device.[3][5][10] Ischys has no sync: your data moves with your normal device backup, or with an export.
Where Ischys is different
- Nothing to pay for. Every feature is in the free app, including routines, charts, personal records, the Apple Watch app and the Live Activity. There are no limits to unlock.
- Your data stays with you. Workouts are rows in a database on your phone. There is no account and no server, so Ischys never holds a copy of your data.
- You can read the code. The whole app is on GitHub under the MIT licence, so the privacy claims can be checked instead of trusted.
Moving your history
Both Hevy and Strong can export your workouts as a CSV file.[6][15] Ischys imports a workout CSV with one row per set and recognises the common column names. If a file does not import cleanly, open an issue with its header row and it will be looked at. You can take your workout history back out of Ischys as CSV or JSON at any time.
Other open-source workout trackers
Ischys is one of several open-source workout trackers. The main difference between them is where your data lives: some are web apps you host on your own server, some keep everything on the phone. All of these can be read, built and changed under their licences. The facts below come from each project's own README, source code or store listing, checked on 20 October 2026.
| Licence | How to get it | Where your data lives | Account needed | Apple Watch app | |
|---|---|---|---|---|---|
| wger | AGPL-3.0 | Web at wger.de, or self-host with Docker. Apps on the App Store, Google Play, F-Droid and Flathub.[17][19] | On a wger server: the public one at wger.de by default, or your own.[17][18] | Yes, on wger.de and in the apps. A self-hosted server can allow temporary guest accounts.[17][18] | No |
| openGym | AGPL-3.0 | Self-host with Docker as a web app. Android app from GitHub releases; on iPhone, a web app from your own server or a build from source in Xcode.[20] | On your server, or on the phone with the standalone phone app.[20] | No. Guest mode is on by default.[20] | No |
| workout.cool | MIT | Web at workout.cool, or self-host with Docker. There is also an iPhone app on the App Store.[21][28] | In the browser when signed out; on the server when signed in.[21][22] | Only to sync to the server.[22] | No |
| LiftLog | AGPL-3.0 | App Store and Google Play.[23] | On the phone, with optional backup to a server.[23] | No.[23] | No |
| Flexify | MIT | Google Play, F-Droid and the Microsoft Store.[24][25] | On the device.[24] | No.[25] | No |
| OpenWorkoutTracker | MPL-2.0[27] | iPhone and Apple Watch, built from source in Xcode.[26] | On the phone, with optional export to iCloud Drive.[26] | No.[26] | Yes[26] |
| Ischys | MIT | App Store for iPhone and Apple Watch. Android and Wear OS are in closed testing. | On the phone. | No. | Yes |
"No" in the Apple Watch column means no watch app appears in the project's repository or App Store listing.
What each one does best
- wger: a community-edited exercise wiki, plus routines with automatic weight progression, nutrition tracking with a food database, body measurements, a REST API and multi-user servers.[17]
- openGym: self-hosted sync across devices, and a muscle map of where your volume went, what is still recovering and what has gone untrained.[20]
- workout.cool: building a workout from your equipment and target muscles, with video demonstrations.[21][28]
- LiftLog: quick lift logging on both iPhone and Android, with optional end-to-end encrypted feeds to share workouts with friends.[23]
- Flexify: offline strength and cardio logging on Android and Windows, with plans, timers and graphs.[24]
- OpenWorkoutTracker: a phone bike computer for cycling and running, with Bluetooth heart-rate, power and cadence sensors.[26]
If you want a server you control, with sync across devices, wger and openGym are built for that. If you want an iPhone and Apple Watch app you can install from the App Store, with nothing to host and no account, that is what Ischys does.
Sources
Sources 1–16 were read on 13 October 2026, and sources 17–28 on 20 October 2026.
- Hevy, App Store listing (United States): https://apps.apple.com/us/app/hevy-workout-tracker-gym-log/id1458862350
- Hevy help centre, switching from Pro to the free version: https://help.hevyapp.com/hc/en-us/articles/38279350428695-What-will-happen-to-my-account-if-I-switch-from-Pro-to-the-free-version
- Hevy help centre, uninstalling and reinstalling: https://help.hevyapp.com/hc/en-us/articles/38223672272791-What-will-happen-to-my-information-if-I-uninstall-and-reinstall-the-Hevy-app
- Hevy, terms and conditions: https://www.hevyapp.com/legal/terms-and-conditions/
- Hevy help centre, features guide: https://help.hevyapp.com/hc/en-us/articles/33106320824727-Everything-You-Need-to-Know-About-the-Hevy-App-2026-Features-Guide
- Hevy help centre, exporting your data: https://help.hevyapp.com/hc/en-us/articles/43708290987415-Exporting-Your-Data-from-Hevy
- Hevy help centre, importing CSV files: https://help.hevyapp.com/hc/en-us/articles/38001424401943-How-to-Import-Strong-App-CSV-Files-and-Export-Your-Data-in-Hevy
- Strong, App Store listing (United States): https://apps.apple.com/us/app/strong-workout-tracker-gym-log/id464254577
- Strong help centre, Strong PRO: https://help.strongapp.io/article/132-strong-pro
- Strong help centre, Strong account: https://help.strongapp.io/article/143-strong-account
- Strong, privacy policy: https://help.strongapp.io/article/232-privacy-policy
- Strong, terms of service: https://help.strongapp.io/article/179-strong-terms-of-service
- Strong, website: https://www.strong.app/
- Strong help centre, sync with Apple Health: https://help.strongapp.io/article/147-sync-with-apple-health
- Strong help centre, export workout data: https://help.strongapp.io/article/235-export-workout-data
- Strong help centre, what is Strong: https://help.strongapp.io/article/228-what-is-strong
- wger, README: https://github.com/wger-project/wger#readme
- wger mobile app, default server and login (source): https://github.com/wger-project/flutter/blob/master/lib/core/consts.dart
- wger, App Store listing: https://apps.apple.com/us/app/wger-workout-manager/id6502226792
- openGym, README: https://github.com/DuarteSantos8/openGym#readme
- workout.cool, README: https://github.com/Snouzy/workout-cool#readme
- workout.cool, signed-out session storage (source): https://github.com/Snouzy/workout-cool/blob/main/src/shared/lib/workout-session/workout-session.local.ts
- LiftLog, README: https://github.com/LiamMorrow/LiftLog#readme
- Flexify, README: https://github.com/brandonp2412/Flexify#readme
- Flexify, F-Droid listing: https://f-droid.org/en/packages/com.presley.flexify/
- OpenWorkoutTracker, README: https://github.com/msimms/OpenWorkoutTracker#readme
- OpenWorkoutTracker, licence file: https://github.com/msimms/OpenWorkoutTracker/blob/master/LICENSE
- workout.cool, App Store listing (United States): https://apps.apple.com/us/app/workout-cool-fitness-coach/id6749820499
Corrections
Ischys is an independent project. It is not affiliated with, endorsed by or connected to Hevy, Strong or any of the open-source projects named on this page, and those names belong to their respective owners. Apps change: if anything on this page is out of date or wrong, open an issue and it will be corrected.