Write an Android App

I need a camera application that allows the user to number a photo with a watermark while taking the picture. Steps . Load app Choose watermark number in lower right corner with +/- buttons or scroller Take picture At that point the saved picture will have the chosen number "watermarked" onto the image in the lower right corner. Optional. If possible I would like to be able to have optional watermark text in the lower center of the photo. I would like the app to sequentially default to next number Lastly. I would prefer to have the app on IPad first but would like IPhone and android later if it works well.