To test an Android APK file with Robotium, the APK must have the same signature as the test project. There are two ways to sign an APK - if built within Eclipse, no resigning is needed as the signatures will match. Otherwise, the APK can be resigned by unpacking it, deleting the META-INF folder, repacking it, and using jarsigner to sign it with the debug keystore.

1. How to re-sign a Android .apk
file for testing

2. A signature is needed to identify the author of the Android application. A
signature mostly contains information like:
First name
Last name
Name of the organization
City
State
Country Code
For more information please have a look at the Android SDK developer guide
http://developer.android.com/guide/publishing/app-signing.html

3. If you want to test an apk file e.g. with Robotium the android app apk and
your test project apk file MUST have the same signature!
There are two possible cases how to sign the apk file. The first one is really
simple,
if you build the Android app you want to test on your own within eclipse you
don’t need to resign the apk file. The signatures should be the same.
The second case is more complex.
If you get the apk file you have to test e.g. from your developers, from jenkins
or from the market you have to resign the app.

4. Do the following steps to resign it with your keystore:
1. Rename the apk file into a zip file, e.g. yourapp_name.apk = Name.zip
2. Unpack/ Unzip the zip file
3. Delete the META-INF folder
4. Repack/ Rezip the folder again to a zip file
5. Rename the zip file again to an apk file
6. Open a terminal window / Command prompt and enter (the jarsigner tool is
located in the bin folder of your installed java sdk

5. jarsigner -keystore ~/.android/debug.keystore -storepass android –keypass
android urAppName.apk androiddebugkey
You’re Done!! Now you can should be able to test against an apk file!