qBitController is a free and open-source app for controlling qBittorrent from an Android device.
The closest would be a folder, synchronized between phone and computer (e.g. using syncthing) where you save the torrent files. Then the client scans and automatically adds torrents from there. It will remove such files, so while at it, you should also configure to save completed torrent files somewhere. When possible, torrent files are a better option (they bring metadata, required if you ever wanted to re-share some content).