Now windows phone 8.1 torrent supports torrent downloading, its a great feature upgrade which also have the option to save the download on your SD Card..
BitTorrent Sync for Windows Phone makes it easy to save and share files via its mobile app. Add two-way automatic backups between remote stations with just a few clicks with directions that guide you step-by-step through the various stages.
Target a folder on your central unit as well as on the smartphone to automatically trigger the recovery of the files it contains. You can also share content with your friends and family on the same principle. A QR Code is generated with each sharing to facilitate the exchange of the decryption key allowing your recipients to then receive your data.