One of the best things about Stubborn Trojan Killer is how easily it deals with Ghost Push, a very dangerous malware that has already infected hundreds of thousands of users. As long as your device is rooted, you shouldn't have any problems deleting it from your device.
Stubborn Trojan Killer can be very useful in certain cases (if your device is infected with Ghost Push, for example), but it's not exactly an essential app to have. In any case, its convenient interface makes it an easy app to use when you need it.
Requires Android 2.3 or higher