Ive written a program for my android device and its installed and working on my phone (S3), BUT ive just lost my PC HD and thought id saved my eclipse android coding folder but I didn't, the program is only a small one but took me a while to perfect so i need to recover it into eclipse to edit it more and save it.
If you have lost a full package structure due to accidental deletion or svn/cvs/git override, select the project> right click> Restore from local history => select the files.
What you can do is since you still have the working app on your S3, you can use something like
Use ES File Explorer to back up the app and retrieve the .apk file.
Decompile using: http://www.decompileandroid.com/, or APK Tool