So, T-Mobile allows you to have unlimited data for certain apps. But when I look at my Mobile Data usage in the System Settings, it's all there. This makes total sense, but is there a way to tell Android to filter out apps of my choosing?
A firewall app will give you control over how individual apps and background processes get online access. You can selectively block/allow each one for WiFi and for cellular connectivity.
If you're rooted take a look at AFWall+
https://forums.androidcentral.com/e...?id=dev.ukanth.ufirewall&hl=en&token=Je1eLtli
If not, NetGuard is a really good non-root option
https://forums.androidcentral.com/e...?id=eu.faircode.netguard&hl=en&token=TkXBh_pF