sniff - Five mobile social networking services

Mobile social networking is a lot like real estate--the secret to success is location, location, location. Useful Networks' sniff (Social Network Integrated Friend Finder) is a permission-based mobile application enabling consumers to locate contacts in real-time, anytime and anywhere, via SMS or on Facebook, providing consumers with a detailed map view of their friends' current locations. The sniff app emphasizes privacy, with all user behavior governed by principles of notice and consent--multiple levels of security guarantee you're only found when and if you want companionship. Useful Networks also mails out multiple confirmation notices to new users reminding them they joined the sniff network and should be mindful of their status and permission levels.

See it at https://www.sniffu.com/ [1]