The icon will only disappear from your iOS device if you accidentally delete the app. You can simply reinstall it.
It’s more complicated with Android devices and the problem is mostly caused by the device, not the app itself. Please try the following:
- if you see the app icon, but you can't open it, delete the shortcut from your home screen and add it again from the applications’ list
if you can't see the app icon on your home screen, open the applications’ list in your launcher find MAPS.ME and add a shortcut to your home screen.
- If you can't see MAPS.ME in the applications’ list, uninstall MAPS.ME manually from your device (Android settings → Apps → All Apps → MAPS.ME → Uninstall)
If the issue continues:
- Open Android settings → Application Manager → Google Play Store (or whichever store you used to download MAPS.ME, e.g. Samsung Apps) and do Force Stop, Clear Cache, Clear Data
- Restart the device
- Reinstall MAPS.ME.