Clutch is a web UI for the excellent Transmission BitTorrent client on Mac.
It will allow you to access and control all your torrent downloads performed on one Mac from the web. The application is easy to work with. Once you've got Transmission running and are downloading torrents, install the bundle. Open that up and choose to start both the Daemon and WebUI from the Clutch menu. You'll have to set up a username and password and note down the url with which you can access your client from any computer connected to the web.
Once Clutch is working and configured, it's really easy to access your Transmission client from anywhere. You'll be able to do the usual set of commands like pause and resume, open, filter, and even check the information for each torrent. Unfortunately, Clutch is only based on the features of Transmission 0.82, so it won't show all the cool new features you get in the latest version. The interface also looks a bit outdated.
Even though it's not based on the latest version of Transmission, Clutch is a very useful WebUI to control your Transmission from the web.