Both iKeepActive and iKeepActive have been voluntarily removed from the App Store last year, but have been re-instated with new versions in the App Sore after the 2015 Holidays. Both applications include updates to their core functionalities to use the newest Apple OS X APIs EventKit and AVFoundation, retiring CalendarStore and QuicktimeKit, respectively. This will fix compatibility issues with the newest versions of OS X. This also means that support for Snow Leopard, Lion, and Mountain Lion have been retired.
iKeepActive has also been updated with some graphing of your progress and muscle coverage from your workout schedule, while the Lite version only focuses on the API update.
iKeepActive
iKeepActive Lite
Jeff