The Hashcards Journey

When I was young, I was taught Quran using a method that stuck with me. There was the “lawḥ” (لوح), “board”, meaning new material to memorize. And there was “murājaʿa” (مراجعة), “review”. You never just learned new material. Every session, you’d work on your board while also reviewing what you’d memorized before. New and old, always together.

I still remember those verses decades later.

Years later, I discovered this had a name: spaced repetition. Researchers had studied it, measured it, optimized it. The science confirmed what generations of teachers already knew: reviewing information at the right intervals transforms short-term memories into lasting knowledge.

In fact, most of what constructed my knowledge on programming and many languages came from learning on Execute Program—an interactive platform that uses spaced repetition to teach TypeScript, SQL, JavaScript, and more. For spoken languages, Mango Languages used the same approach to make vocabulary and grammar stick. These experiences showed me firsthand how powerful the method could be.

I wanted to build a spaced repetition app that I would actually like to use. When I looked at the existing apps, something felt off.

The Problem with Flashcard Apps Today

Most flashcard apps—Anki being the most well-known—are powerful, open-source, and have been around forever. But “powerful” often means “complicated.”

The interface is stuck in a desktop-first era. Hamburger menus where you’d expect swipe gestures. Settings buried under layers of menus. Features that most learners will never touch, cluttering the experience for everyone else.

I wanted something that just worked. Something that would let me focus on learning, not managing a system.

The Inspiration

I stumbled upon a command-line tool with a web interface called hashcards that took a refreshingly simple approach. No complicated settings. No sync conflicts. Just cards that worked exactly as you’d expect.

What caught my attention was the philosophy: keep things simple, predictable, and get out of the learner’s way.

I wanted to bring that philosophy to mobile.

Teaching Spaced Repetition

Here’s the thing: most people have never heard of spaced repetition. They know flashcards, sure. But the science behind when to review? That’s still hidden away in academic papers and Reddit threads.

We built a tutorial deck that teaches itself. One of the cards asks: “How does spaced repetition work?” and the answer explains the scheduling algorithm. You learn the system by using it.

The Memory Insights screen shows you what’s actually happening. Your cards moving through states: New, Learning, Review, Relearning. Stability (how long until you’ll forget) and difficulty (how hard the card is for you). Lapses are shown without shame. Everyone forgets, and the algorithm uses that information to help.

“Infinite knowledge, with infinite memory.”

That’s the vision. Not a feature list. A possibility.

AI-Powered Card Generation

You can always create cards manually for free. That’s the core of the app and it works great.

But we also built AI generation to unblock the creation process when you need it. Snap a photo of your notes, scan a PDF, point your camera at a textbook, or just describe what you want to learn in chat. The AI generates cards from your content.

This is a paid feature because we use high-quality models for both text and vision. New users get free credits to try it out, and you can purchase more when you need them. One-time payments, no subscriptions.

What’s Next

We’re just getting started. The foundation is solid: scheduling that works, sync that’s instant, AI that unblocks creation.

More ways to learn: Language-specific decks, math by grade level, science and history modules. Learning paths that adapt to what you’re studying.

Your models, your way: Bring your own API key and choose your preferred AI. Claude, GPT-4, or run locally. The flexibility to use what works for you.

Web access: A web app for studying at your desk. Same cards, same progress, different screen.

If you’ve read this far, you might be the kind of person who would use Hashcards. It’s free on iOS and Android.

Knowledge that stays. Build cards. Then remember them.

Download for iOS · Download for Android

Curious about the technical details? Read Building Hashcards Mobile App for a deep dive into the architecture.