Torrentula is available for download from Cydia, which means you will have to jailbreak your iPhone to use it… The app also requires the latest version of Jiggy Runtime to be installed on your iPhone. Check this out for more information about Jiggy Runtime. After doing that, add the following source in Cydia: http://itouch.rockt.es/repo.xml
Sunburst, the developer of Torrentula explains what to do next:
Download .torrent files to your device with the HistoryDL.app (recommended) or the Safari Download Plugin into the mobile (or root)/Downloads folder. The program will scan your mobile (or root)/Downloads folder for new torrent files, and will import any valid torrent files regardless of their filename or extension. When a torrent has finished downloading from peers it will be automatically moved to mobile (or root)/Media/Downloads when selected. Note: Torrents continue downloading even when program is closed. A device restart can often activate/fix stubborn torrents.
Torrentula will then let you browse torrents site such as MiniNova and will let you download BitTorrents straight to your iPhone.
I haven’t tried this app myself but iPhone Download Blog reader Jenster sent me this tip saying it’s working great. Try it out and let us know what you think by leaving a comment.