GLTools puts graphics optimization on Android in your hands
GLTools is a custom OpenGL ES driver that's compatible with any familiar OGL ES 2.0-compatible GPU and ARM or x86-based CPU. Experienced users could think of it as a ChainFire 3D alternative. Whisking control away from the system and into users' hands, this app has enough toggles and switches to turn you into an optimization obsessive. Here's a glance at what you can achieve with it!
For starters, you can change the resolution and color depth for any app and game, even if they don't support this by default. You can also decompress/recompress and resize textures, or optimize shaders while you're gaming.
You can also enable MSAA and CSAA filtering if your GPU supports them, and measure performance with an on-screen FPS counter. All your default settings are backed up, so if something goes haywire, just restore.
For owners of older, or low-end devices, the goal might not be better graphical quality, but rather the opposite - reducing image complexity to obtain better performance. Like any respectable graphics tool, GLTools travels both ways.
If a heavy 3D game is giving you trouble, force rendering to 16 bit, downscale textures, minimise the resolution, and experiment with other settings. It doesn't really take flashy graphics to enjoy a game, does it?
Okay, enough explanations! Download GLTools and get to work. The app can be obtained for free from the XDA Developers board, or bought from Google Play as a way of supporting the developer.