The name is kind of self explanatory. With this app, you can designate a folder(s) that the app will look at for pictures/wallpapers, then specify how often you want it to switch. Then the app just switches your wallpaper everytime the predetermined amount of time elapses. I was bored today so I set it for every 30 minutes. Its really cool to check your phone and frequently see a different wallpaper, keeps things a tad exciting. Initial observations show that having this running in the background does not really adversely effect battery life. I have noticed no change in battery life using it the whole day today at 30 min intervals. It also has a switch now button so you can just open the app and quickly switch your wallpaper. There is also a widget that you can press and it will instantly change your wallpaper. The only downside here is that the widget takes up an entire row of icon space. Anyway, its a cool little app, not large by any means, and should add a little fun to your phone. I highly recommend at least checking it out.
One thing I forgot to mention is that it autocrops the wallpaper. This feature works extremely well and I have not had any problems with it and larger wallpapers. In addition, if the wallpaper is a bit too large, it will put it in a letter box form (black bars on top and bottom) that still has the picture nice and large and proportionate. Here is the QR code