Interactive quiz/training tool: an instructor can use Quizzi to pose questions to a class via SMS, and receive and tabulate their responses in real-time. Think "clickers" but without the infrastructure and cost.
Each student/trainee uses their personal phone to exchange SMS with the instructor's Android phone. An instructor asks a question to the class, optionally also sending the question to the students' phones via SMS. Students reply with their answer (either free-text or multiple choice), and the answers are displayed in real-time in the app.
This allows the instructor to gauge understanding and increase engagement.
Question sets can be loaded from the memory card, or ask questions off-the-cuff.