App Control is an Android app for rooted devices that allows you to control a series of system settings for individual apps. Much like SetCPU, you have the ability to overclock and underclock based on which apps you’re running, and additionally you can set font size, WiFi state, screen orientation, and most importantly (to me) screen timeout for individual apps.
This combo allows you to set the perfect settings for my current favorite demonstrative game: Ingress. You can set it to cap the CPU at ~800mHZ, turn off the WiFi as I don’t want to accidentally get stuck in someone’s WiFi hotspot named Linksys, and set the screen timeout to five minutes.
While the application is still in its very early phases, having evidently been released yesterday, the plans for the future look bright for App Control with features such as per-app volume control, permission controls, and Internet toggle per app listed by the developer as either planned or in development.
The app is not currently in the market, so you’ll need to head to the development thread at XDA (linked below) and download it from there. While there doesn’t seem to be anything you could do to wreck your system with this, it’s a good idea with anything that sets the CPU speed to go ahead and make a full nandroid backup just in case you manage to softbrick your system with a CPU setting your device doesn’t like.