ACT Flashcards from Magoosh - Everything you should have learned in high school
Zorbi - Spaced-Repetition Flashcards - Other tools are built by boomers, Zorbi is built by students.
Grammarly - Clear, effective, mistake-free writing everywhere you type.
Mochi - Write notes and flashcards with Markdown and study them with spaced repetition.
Eduflow - Digital learning that actually teaches students something
SmartCards+ - Spaced Repetition Software for iOS. Modern, powerful and easy to use.