Torrent Downloader is an app that, as the name suggests, lets you download Bit Torrents directly using your Samsung Z3 smartphone. The app promises to be a fast and easy "Lightweight yet powerful bittorrent app" and gives you some powerful features, such as being able to select the files you want to download within a torrent, supports magnet links, and lets you select your desired storage location.
This app is available for the Samsung Z3, but there will be support added for the Z1 soon. and is now available for the Samsung Z1.