Hello android masters, Android recruit reporting. Could someone tell me about android UID? I searched but could not find any usefull information and/or working sample prog about UID. I programmed 2 apps: 1 to create a file on the android SD card. 2nd app reads the text from the SD card file. additional info: - Both app use the same android vm on my eclipse Android SDK - package names should not matter, but I gave them different names: com.xxx and com.yyy The text is written to my logcat in my linux terminal. I could read the SD file created by the other app. I did not use sharedUserId. I thought that every app gets it's own UID, and that they could not share files. Could someone tell me why I can, without setting UID? 2nd question: How is UID used practically? didn't see any sample programs that use UID. Many thanks in advance.