The Wallet Reminder SB21 is a quick alarm to prevent your wallet from lost. It can be easily put into any wallet since the size is half of a credit card. Download the free app iStuffFinder from App Store or Google play store, and combine with Wallet Reminder SB21 device, you will never lose or leave your wallet behind. As a remote shutter release for self-portraits or to prevent blur by shaking camera. Moreover, the app will take a GPS snapshot when your wallet is away from your phone for a certain range you set, which let you know where your wallet is left at. This device works with your iOS/Android devices.