So I'm selling my old Meizu M2 Note which is running Flyme OS that doesn't allow me to encrypt the whole phone. How can I ensure the data is actually gone before selling? Normal wiping doesn't erase everything.
Yes, it is. And I finally found the solution: as Avast! support told me, you can still use Avast! Mobile Security to securely erase your phone (by overwriting data), it's just a hidden feature. You just have to deactivate the Device Administrators permission for the app: https://support.avast.com/en-us/article/65 Then you just use the "erase device" feature and you are fine.
