gigacount is a smartphone app that simulates radiation measurement. The camera takes pictures of objects. It stores the pictures as files or transmits them to a service on the network. A user sees the preview of the camera and a number that represents the (estimated) value of radiation. She can set up the application to display random numbers and which format/unit. It also includes options to alter preview color or display a static meter background.
Darwin Wallet enables blind and visually impaired users to quickly recognize paper money. It uses the phone's camera to detect currency denominations for U.S., U.K., Canadian, European Union, and Australian bills. Simply hold the bill in front of the phone's camera, and the app will speak its value. The app uses the phone's camera and OpenCV (via Android NDK) to analyze and identify the currency image.
Quizzley is a simple site that allows you to create a quiz or a poll and distribute it to your audience. Once your audience pairs with the quiz/poll, their smartphone will automatically transform into the voting pad. It's a fast way to interact with your audience; no authentication or registration are needed.