Is It Snappy? 1.0.4

Use your iPhone's high-frame-rate camera to measure the input-to-output latency of your text editor, device, game console, or television. Simply record a video containing the button press and the resulting effect on the screen. Is It Snappy? provides a frame-accurate scrubbing UI where the precise input and output times can be marked. The difference in milliseconds is displayed.

With Is It Snappy?, the responsiveness of a device, text editor, display, or video game can be objectively quantified.