RoutineLab Universal Interval Timer vs Spaced Repetition Tracker

RoutineLab Universal Interval Timer has no write-up on Specifiction yet; its figures are above.

Spaced Repetition Tracker is an iOS and macOS study app that logs sessions, records recall difficulty, and schedules future reviews. Its SM-2 method adapts review timing to ratings of Easy, Good, Hard, or Extremely Hard; users can also choose fixed intervals or predefined and custom plans. Coursework can be organized into subjects, groups, and topics, with separate tracking for multiple subjects. The app provides a review queue, visual timeline, calendar and session history, reminders, and iOS widgets. It can schedule topics studied through textbooks, lectures, question banks, notes, videos, cases, and flashcards. Review events can be added to Apple Calendar and Google Calendar. The free plan allows up to two subjects with six topics each and unlimited sessions. Paid choices include $5.99 a month, $29.99 a year, $49.99, paid once for Unlimited Access, and $34.99, paid once for Unlimited Access (Family). User data is stored locally and synced through Apple's iCloud CloudKit private database; the privacy policy says it is not shared with third parties or external services.