//download data.ab (encrypted) and DONOT GIVE ANY PASSWORD when prompted
adb backup -f ~/data.ab -noapk app.package.name

//decrypt and extract the data.ab [this worked most of the time except for few instances ] 
//this will output all the contents of app into 'apps' directory
dd if=data.ab bs=1 skip=24 | python -c "import zlib,sys;sys.stdout.write(zlib.decompress(sys.stdin.read()))" | tar -xvf -


//SOURCE: http://blog.shvetsov.com/2013/02/access-android-app-data-without-root.html