How to build a vocabulary learning app for iOS
What a vocabulary learning app needs
- Word entries with definition, part of speech, and an example sentence
- Decks or lists you can group by topic, exam, or language
- A spaced repetition schedule that adapts to how well you recall each word
- A review session with a clear right or wrong response per card
- Audio pronunciation of the word and the example sentence
- A daily word and a streak to build the habit
- A Home Screen widget showing the word of the day
- Progress stats: words learned, due today, and retention over time
The scheduling logic is the core. Everything a learner feels, the sense that the app knows what they are about to forget, comes from getting the review intervals right.
How to build it with AppFlight
Describe it in plain English, for example: "A vocabulary app with decks of words, each with a definition, part of speech, and an example. Review words with a spaced repetition schedule so hard words come back sooner and easy ones stretch out. Read the word and example aloud, show a word of the day, track my streak, and put the daily word in a widget." AppFlight plans the screens, generates native SwiftUI, and launches it in a live simulator so you can run a review session immediately. To generate fresh example sentences, AppFlight can connect OpenAI, with the API key kept server-side in your own Supabase rather than shipped in the app. You iterate in plain language, for example adding a quiz mode or import from a CSV.
Monetization for a vocabulary learning app
The proven model is a free starter deck with a paid upgrade. Free users get one deck and daily reviews; the subscription unlocks unlimited decks, audio, detailed retention stats, AI-written examples, and the daily word widget styles. Add a RevenueCat paywall to manage subscriptions, and use Superwall to test paywall designs without shipping an update. Learners who study for an exam or a new language tend to commit, so an annual plan often outperforms monthly in this category.
Shipping it to the App Store
When the app is ready, AppFlight signs the build, uploads to TestFlight so you can study on your own device, then submits to the App Store with metadata and screenshots from the simulator. If Apple rejects the build, AppFlight reads the reason, works on the fix, and resubmits. If you use AI to generate example sentences, review the output for quality before it reaches learners. Apple reviews every app, so a submission is not the same as an approval, but the whole pipeline runs without you opening Xcode.
FAQ
What is spaced repetition and do I need it?
Spaced repetition shows a word again right before you would forget it, stretching the interval each time you recall it correctly. It is the engine behind most serious vocabulary apps, and it is mostly scheduling logic on top of your word data.
Can words be read aloud?
Yes. AppFlight builds native Swift, so the app can use the system speech synthesizer to pronounce a word and an example sentence. You can also wire OpenAI in to write fresh example sentences for each word.
How do vocabulary apps make money?
A free starter deck with a subscription for unlimited decks, detailed progress, audio, and a daily word widget. A RevenueCat or Superwall paywall is the common setup.