Drivetrain, an iPhone app rejected by Apple, doesn’t download torrents itself. It’s a remote-control device for a desktop / laptop BitTorrent application called Transmission. It’s not surprising that app developer Aaron Scott, who sells under the name Maza Digital, got a rejection letter from Apple that said, “This category of applications is often used for the purpose of infringing third party rights. We have chosen to not publish this type of application to the App Store.” What’s surprising is that Trackr, an RSS reader that also remotely controls BitTorrent, passed Apple’s screening and is available in the iTunes App Store for $2.99. Why is that? I’ve asked Apple and will update if I hear from them.