When developing and publishing Android from Eclipse you might run into this error on your device.
Re-installation failed due to different application signatures.
You must perform a full uninstall of the application. WARNING: This will remove the application data!
Please execute ‘adb uninstall dk.spacetech.app’ in a shell.
The error is due to a different application signature, meaning it does not detect it as the same application. This typically occur after you have publish your Android app on the Play Store and afterwards deploy a modified version from Eclipse.
What you need to do is uninstall the Play Store app version of your application. You can do this either by going to your application on your device and uninstall it in either Settings -> Application and uninstall or goto Play Store -> My app/downloads.
You can also do this in the command prompt, navigate to adb, d:\Android\android-sdk\platform-tools or similar depending where you have put the sdk. Then run the command
adb uninstall dk.spacetech.app
adb uninstall [-k] <package> – remove this app package from the device
(‘-k’ means keep the data and cache directories)