I've used Fasthub for Android before which was great. There is also a fully libre / FLOSS version that has the paid features added in (which you can do since the entire app is GPL). I remember a Github issue where the creator was mad about it, but well, if you pick GPL you should know what you're getting into.

https://github.com/k0shk0sh/FastHub https://f-droid.org/en/packages/com.fastaccess.github.libre/