The Mego Optoelectronics LM131 is not the most powerful Android device to cross my desk recently but it is the most interesting. It runs Android 4.2 on a 1GHz CPU with 1GB RAM and 8GB internal storage. It also has Wifi, a microSD card slot, USB Host, and ports for both HDMI and VGA (in, not out).
Even though this projector just cleared the FCC, it has been available on AliExpress and eBay (for about $300 – $330) for some time now. I'm pointing that out because there's some contradiction between the FCC filing and the retailer listings.
Both confirm the speaker and the touchpad on the upper surface of the projector, but the eBay listing claims that the projector is capable of 260 lumens, while the user manual in the FCC filing lists the brightness as 100 lumens (different models, perhaps).
The user manual also mentions that the LM131 supports displaying "PDF, photos, Excel files, Powerpoint presentations and various video files", which is a nice start, but since both the manual and the Ebay listing mention that this projector ships with Google Play there's no reason to limit yourself to those formats.
The one true limitation (other than battery life) is the projector's resolution. It's capable of 854 x 480 resolution, which is a little low. For about $100 more you can find an Android-based projector which boasts a resolution of 1024 x 600 (although I can't tell you which version of Android is running on that model).
Should you ever have a need to blowup a small Android screen to 150", this is your gadget.