Are you interested in checking out your jpeg, png, bmp, and gif files to see if they are properly exposed? It's easy with this image histogram generator. This application loads those formats in any size, large or small, and allows you to see how luminance and color data is distributed throughout the image.
I wrote this program so that I could get a nice large detailed tonal histogram of my camera photos as well as images that I downloaded or store on the device. I was even able to display a histogram of an 8MB 100% quality JPEG from my 16MP camera! (with some wait time for processing of course).
The application allows you to select an image from the built-in android gallery as well as browse your device with any attached storage like a Micro SD card inserted into your phone or other device.
So now you and I can check our work afterward to make sure that the exposure is technically correct as well as check for either red, green, or blue color issues. Sometimes only one channel like red can be underexposed or over exposed, causing an issue with the overall photo. I use this program to check for difficult-to-spot issues like that.
I'm offering this up on the Android market to help others benefit from my efforts in solving a problem I had.