So I recently sold an Android Tablet and reset it to factory Froyo. I had sideloaded a bunch of .apk's and actually shown pics of the tablet w/ Kindle app installed in my auction. As a result, I feel obligated to sell it w/ at least the ability to install that app intact. My question is, do .apk files contain merely the app (like a .exe), or do they have any embedded personal info? I don't mind giving a disk or SD card full of apps. I just don't want to accidentally give away my user info.