A simple Android App Engine Project

I need a simple Android-Appengine application for my school project. The app will send a request to the appengine with user info and some data, then the appengine will do some calculation and reply with some stored information. The calculation part can be left empty for me to put my algorithm later. It can be like user choose 1,2,or 3, then the appengine reply with dataset-1, 2,or 3 from the datastore in JSON format. You can put some dummy data inside. The appengine needs to log all the user request, and allows me to download and update the stored information like in cvs format. The code should be properly commented, especially where to put the logic part. My logic will not be very complicated, it will be like the appengine looks at the user age, then retrieve the data that matches the age range. I will expand this part myself. No need android UI design. No need web interface.