For raw power and customization, Anki remains the gold standard.
It's free on desktop and Android, costs $25 on iOS, has a battle-tested SM-2 algorithm, and benefits from a massive community deck library.
However, Anki requires manual card creation and has a steep learning curve. Alternatives like RemNote or Quizlet offer simpler onboarding.
Key distinction: Anki helps you memorize facts through flashcards. If you want to reinforce your own notes without creating cards manually, tools like Daily Brain Bits take a different approach by resurfacing notes from your personal knowledge base using spaced repetition principles.