I would like you to choose an open source android application such as Serval (https://play.google.com/store/apps/details?id=org.servalproject&hl=en) and add a new feature. You will remove the current GUI as much as possible.
When the app is first run it will create a public and private key pair and ask the user to choose a non unique user name. This will be saved on the device.
The first screen will have a three buttons: Manage Reviews, Manage Friends, and read reviews.
Manage reviews will show a list of reviews the user has created and a button 'Create New'. Clicking on a review will allow the user to modify the review in a similar window as the 'Create New' window. Both windows will allow the user to rate the restaurant on a 5 star system, and input address, restaurant name, and a 200 character review. Only the name of the restaurant and the rating are required. All the reviews will be stored on the phone and digitally signed using the private key.
The phone will regularly...