But if you don’t want to jailbreak your device, there are a few third party services that allow you to install apps like iTransmission without jailbreaking your device. If you have a jailbroken iOS device, you can get iTransmission from Cydia for free. Since the app is not available on the App Store, the installation method will be slightly different. It uses the same backend as Transmission, the BitTorrent client for Mac. ITransmission is a native BitTorrent client for iOS.
Although no official BitTorrent clients are available in the App Store, you can still get full desktop class torrent download experience on your iPhone, iPad and iPod Touch.