Its a mini panel-mountable HDMI monitor! So small and simple, you can use this display with any computer that has HDMI output, and the shape makes it easy to attach to a case or rail. This backpack features the TFP401 for decoding video, and includes the attached display so its plug-n-play.
The TFP401 is a beefy DVI/HDMI decoder from TI. It can take unencrypted video and pipe out the raw 24-bit color pixel data - HDCP not supported! The 5" display is 800x480 resolution, which is just enough to run most software, but still small enough that it can be used in portable or embedded projects without the bulk.
You can even power the entire display from a USB port. With the default 5" 800x480 display and 50mA backlight current, the current draw is 500mA total. You can reduce that down 370mA by running the backlight at half-brightness (25mA). With the backlight off, the decoder and display itself draws 250mA. If you want more backlight control, there's a PWM input, connect that to your microcontroller or other PWM output and you can continuously dim the backlight as desired. The display has a microUSB port.
Adafruit have two versions, one is video only and one is video+touch. This version does not have a touch screen capability. If you want a screen that you can poke at, get the +touch version (coming soon!)
In particular, they suggest it for use with single board computers (or desktop/laptops!) with DVI/HDMI output like the Raspberry Pi or BeagleBone Black. You can power the driver over USB as long as your computer can supply 500mA on the USB port, and then feed it video via the HDMI port. Please note the TFP401 decoder chip does not contain a video scaler, it will not resize/shrink video!