Waves: Bible Verse

Context

Waves delivers Bible verses curated to what someone is actually going through. A daily mood check-in shapes which scripture surfaces; lock and home screen widgets refresh through the day; and an AI chat explains verses, generates devotionals and answers faith questions in context. It runs on a subscription with a free trial.

The problem

Devotional apps have a retention problem shaped like a calendar: a verse-of-the-day is the same verse for everyone, so it stops feeling addressed to you by roughly day four.

The product bet is that relevance beats volume — that a verse chosen for how you feel today outperforms a larger library served generically. That makes personalisation the product, not a feature of it.

What I built

• Built the iOS app in React Native and TypeScript
• Implemented the mood check-in slider that drives verse curation from a user's daily emotional state
• Built Waves Chat on OpenAI — verse explanations, personalised devotionals and open faith-based questions, with prompting tuned to stay grounded in scripture rather than freelancing
• Built lock screen and home screen widgets that refresh on a schedule, keeping content present without requiring the app to be opened
• Implemented customisable reminder notifications and devotional streak tracking
• Integrated in-app purchases and subscription management across weekly, monthly, six-month and annual tiers with a free trial

Engineering challenges

Widgets are a different execution environment. Lock and home screen widgets refresh on a schedule the OS controls, not on demand. Getting fresh, personalised content into a widget means pre-computing what it will need and respecting a tight memory and time budget — you cannot call an API when the widget wakes.

An AI that has to stay in bounds. A faith chatbot answering “what does this verse mean” has an obvious failure mode. The work was prompt design and grounding — keeping responses anchored in scripture and appropriate to a devotional context rather than free-associating, in a domain where getting it wrong genuinely matters to the person reading it.

Subscriptions across six price points. Weekly, monthly, six-month and annual tiers plus a three-day trial, with receipt validation, restore-purchase, and state that stays correct through cancellation and re-subscription.

Outcome

Waves holds a 4.8 star rating from 246 ratings on the US App Store and has shipped seven releases since launching in April 2025, including a mood check-in feature added in 2026. It is a paid product with a real subscriber base.