I’ve used “qBittorrent Remote” from the Play Store but I’m trying to get off the Play Store, and use FOSS.
Transdroid works pretty well. It’s not the most up-to-date app, but it gets the job done. It supports multiple torrent applications including qBittorrent and it’s fully open source.
Second this, it’s my daily driver on android to control my qBittorrent instance, and so far I haven’t missed any kind of functionality, it just does everything I need.
For basic tasks (uploading a torrent, changing download path, etc) I use qBittorrent Manager and it’s pretty good.
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nzb360 is not FOSS but the dev is awesome and a great person to support.
It’s more for full *arr stack management but qBit is in there as well.
qBitController (Control qBittorrent from your Android device) https://f-droid.org/packages/dev.bartuzen.qbitcontroller/
