Transdroid

Allows you to manage your torrents. All popular clients are supported: µTorrent,
Transmission, rTorrent, Vuze, Deluge, BitTorrent 6, qBittorrent and many more.
You can view and manage the running torrents and individual files. Adding is
easy via the integrated search, RSS feeds or the barcode scanner. Monitor
progress using the home screen widget or background alarm service.

See also https://f-droid.org/packages/org.transdroid.search and https://f-droid.org/packages/org.transdroid.lite.