TouchTone

TouchTone is a 2015 puzzle video game for iOS devices by Mikengreg, a two-person indie game development team made up of Mike Boxleiter and Greg Wohlwend. The player monitors phone calls as part of a government surveillance program to find public threats. The player unlocks chains of emails by completing a series of puzzles wherein a beam is reflected around a room to a set destination. TouchTone core concept grew from a two-day game jam immediately following their 2012 release of Gasketball, but only found its hacker theme following the mid-2013 Edward Snowden global surveillance disclosures. The tone of TouchTone story grew from satirical to serious over the course of the game's development.

Dual-tone multi-frequency signaling (DTMF) is an in-band telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones supplied to telephone customers, starting in 1963. DTMF is standardized by ITU-T Recommendation Q.23] It is also known in the UK as MF4.