iOS
All iPhones are compatible. The synchronisation with Apple Watch is not available.
Android
If you cannot download Step from the Play Store, your smartphone is not compatible. You can check the compatible device list here.
Step supports all the latest versions of Android up to 5 (Lollipop).
Unofficial stores
You cannot download Step from Aptoid or other unofficial Stores.
Smartwatches
You can only connect to Step smartwatches running on Wear OS.