There is no launcher for google appengine like you have on the windows environs. However there is a workaround.
Problem is I copied everything to my ~/Downloads/google-appengine-launcher folder. It worked okay. In the shell I just cd to the above path and do ./GoogleAppengineLauncher.py; it works!!
But since that being a user specific folder I moved it to another generic location: /usr/share/apps, and I added a symbolic link to the above script as follows:
ln -s /usr/share/apps/google-appengine-launcher/GoogleAppengineLauncher.py /usr/bin/google-appengine-launcher
Now I do Alt+F2 to bring the Run dialog, and type in google-appengine-launcher, appengine application windows loads, but there is an error message saying it can't load icons...why is this so? How to fix this?