Mochi - Write notes and flashcards with Markdown and study them with spaced repetition.

Harken - Flashcard app using smart repetition to improve your memory

Yak Tack - remember. words.

MemoStack - MemoStack is a flashcard software that help you memorize more things with less effort. It works great for test preparation, language learning, and more.

Zorbi - Spaced-Repetition Flashcards - Other tools are built by boomers, Zorbi is built by students.

Locked.app - Do you often forget if you've done something important?I keep coming back to check if I've locked the doors.You can check the toggle when you close the door or something.