I have used FireFox on home computer and smart phone for several years synced, have had no serious issues. I have a Moto Pure Edition phone which needed to be sent back in for factory repairs, recently. When it came back from repair facility everything had to be reinstalled. All apps seem to be working except my FireFox app it installs without any issues, sync's without any. The problem is every time the phone is powered off the FireFox app uninstalls on its own. Power the phone back on the FireFox app has to be reinstalled and synced again and message says it has never been synced. The account is always the same. The app seems to work fine until the phone is powered off then needs to be reinstalled start over, this is every time.