Well, Apple doesn’t usually allow these category of application on the App Store. But it’s not possible that all of the applications would come into their view while approving them. One such app which has made its way to Apple Store is a bit torrent client, a transmission RPC that lets you download torrent file on an iOS device and open it right from the application.
This doesn’t mean that this bit torrent client would download torrent files from the web. However, you could do the transmission from your Mac to an iPhone, iPod touch or iPad with the help of transmission RPC. Once downloaded, opening a torrent file from iDevice is another advantage. Though the downloading process happens on the transmission server, but you could see it from the device as well. And control the activity remotely from the device.
If you had been looking forward to download a bitorrent client from App Store, this is the apt solution. Of course, in future, Apple might not approve these apps accidentally or even pull this application. Transmission RPC comes at a price tag of $1.99. You could also stick to the free application of Transmission RPC if you don’t want to shell out these much bucks.