[Zubersoft]

If you are having the same issue with multiple apps, that points to a potential issue with the hardware. Have you tried factory resetting/powerwashing the device and reinstalling the apps to see if that has any impact? Make sure to backup your library in MobileSheets under Settings->Backup and Restore->Backup Library if possible before doing this to ensure you can restore your library later. You'll want to store the backup file somewhere safe (i.e. in the cloud and not on the device).

Mike