Denis Desjardins released El Capistan as a simple tool for saving snapshots of settings on the popular Strymon El Capistan dTape Echo effect. This is similar to the way vintage gear settings were stored on paper or Polaroids, since they did not have presets to save into.
This $3 app is a lot cheaper than a roll of film, and includes some helpful reference guides.
El Capistan iTunes Description:Catalog your favorite settings for the Strymon El Capistan tape echo pedal. Save and name up to 24 presets. Lock your presets to prevent accidental editing during a live performance.
The app also includes a quick reference to all El Capistan modes of operation as well as tips. A virtual tape machine displays tape head configurations and an animated tape reel.