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. Try the following:
Uninstall MAPS.ME manually from your device (Settings –> Application manager –> MAPS.ME –> Uninstall)
- Go to the 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.