Lucky Draw is an interesting app in that it doesn't seem to be necessary until you use it and find that the random number generators are quite good at being absolutely unpredictable. Once you realize just how hard it is to program a random number generator, let alone multiple generators for different situations, Lucky Draw becomes a relatively useful app in many situations.
In the case of Lucky Draw, there is a list of functions--things like a six-sided die, a coin flip, and a rock-paper-scissors simulator--and you can tap any of them and they will run automatically until you press stop. It's not a game so much as a useful tool if you need a quick draw. There are other apps that offer all of these functions, individually, but having a single app with multiple random-luck options in it is quite useful. At the same time, it could use some work to clean up the interface and offer a larger range of options.
If you need a random number generator, or an app that will provide basic functionality for things like coin flips or dice rolls, then Lucky Draw is a useful tool. It is not a powerful app, nor is it particularly attractive, but what it does, it does very well.