This is an unofficial Android port of powerful command line BitTorrent client aria2. aria2 is a lightweight download utility – with footprint of ~4Mb and about as much of Java overhead, specific to this port. It supports everything, one expects from modern torrent downloader: selective file downloading, prioritizing chosen file segments (e.g. watching film while downloading it) and much more. Usage documentation: http://aria2-android.sf.net/faq/ .
This application is NOT yet another Android remote control for desktop BitTorrent client! It embodies actual binaries of aria2, built for ARM and x86 with support for variety of Android versions, ICS and Lollipop included (if you see this text, your device is supported). More Info »
Note, that you DO need a frontend (e.g. remote control app) to download torrents with this port. All it does is launching aria2 binary with sensible parameters in user-friendly way; scheduling and controlling downloads have to be done by another app. For this you can choose between variety of third-party aria2 clients, developed by enthusiasts. I recommend Transdroid (free remote control app for large number of BitTorrent clients: https://play.google.com/store/apps/details?id=org.transdroid.lite ), but you can also try to some other client (not tested by me yet, please write me if you are able to get any results with them):