CarePhone protects users from making embarrassing phone calls when they are at their worst. It is a proof-of-concept application I wrote over five days with two friends for a human-computer interaction course. The edges are very rough because we didn't have any prior Android experience and were on a tight schedule. We used Google APIs for the native app and Processing for the puzzles.
The user chooses a Google contact group that contains all their sensitive contacts and a time interval when they are usually "weak". During this interval any call to a protected contact is first vetted by the phone: the user has to solve a puzzle. The idea is if the user can solve the puzzle they have enough mental faculties to maintain a coherent conversation. The application is safety-aware: phone calls to unprotected contacts (e.g. emergency numbers) aren't interfered with.
It was fun doing the presentation and we managed to get laughs from the audience—it is a very tongue-in-cheek concept, and we made sure to reflect that in the presentation.
Watch the video for an overview of the functionality.