Android Oreo (8.0) introduced the ability for password managers to autofill usernames, emails, and passwords in nearly any app on the device. On most Android devices, you can change your autofill provider from the Settings app.
However, some heavily customized versions of Android, such as Amazon's FireOS, hide the option to change the autofill provider. Hidden doesn't mean gone, though, and that's where this app comes in.
Autofill Changer is a super simple app to change your autofill provider. That's it. Tapping the launcher icon will bring you directly to the native autofill selection screen. If that screen can't be opened, Autofill Changer will tell you why.
PLEASE NOTE: If Autofill Changer can't open the autofill screen, it means your manufacturer has disabled it. There's nothing I can do about that.
This app is open source! Check it out: github.com/zacharee/AutofillChanger