True or Lie was a 2009 iPhone novelty app associated with FEYNMAN. The product archive now maintained on the FEYNMAN website describes a detector-style interface connected to input from a headset microphone. Contemporaneous launch coverage also identifies the application. That historical identity should not be confused with similarly named games released later.
A convincing display is part of the performance
The interesting design idea is theatrical. A meter moves, a participant answers a question and the group waits for a result. The screen gives the activity a familiar shape even when the underlying process does not justify the interpretation people attach to it.
The product archive explicitly frames True or Lie as entertainment and does not endorse it as an accurate scientific or medical lie detector. This is the essential distinction when revisiting the app. A meter-like display is not evidence that someone is being honest or dishonest.
Keep a party game comfortably playful
If you recreate the spirit of this kind of novelty game, agree in advance that the outcome is pretend. Use harmless questions about imaginary scenarios or obvious preferences. Avoid making private disclosures, accusations or relationship decisions depend on a result generated for amusement.
A participant should be able to decline without becoming the subject of the joke. The most enjoyable version gives everyone a role in the performance and makes the comic premise clear, rather than trying to persuade someone that the phone knows something about them.
A useful piece of early App Store history
True or Lie illustrates how quickly developers experimented with microphones, touch screens and familiar real-world instruments. This profile does not confirm current availability or validate the original sensing claims. Its lasting interest is how a simple visual metaphor could turn a phone into an instant conversation piece—and how clearly entertainment needs to announce its limits.