The following apps are available on the App Store:
• Switch Access Training with Music (goo.gl/6ufDSY), and
• Switch Access Training with a Camera (goo.gl/B8buqQ),
as is the OS X program
• Wordwise Reader (goo.gl/F81Y34).
"Random Countdown Timer with Switch Access" is near completion, but has taken a back burner to "PorkRinse Random Sentence Generator with Sensible Nonsense."