Posture habit coach with streaks

The idea

Every desk worker has caught their reflection mid-slouch and promised to fix it, and none of them have. Posture is a habit problem wearing a fitness costume: the exercises are trivial, the remembering is everything. Nothing on the App Store owns this — posture apps are either dead reminder utilities or buried features inside general fitness apps, while the insecurity itself gets bigger every year that screens do.

GoTall showed the playbook: one insecurity, one app, an onboarding quiz that ends in a tuned paywall, subscription revenue in months. Posture is the same play aimed at a larger adult audience with better science underneath it. The wedge is visible progress: a weekly side-profile photo scored on-device for forward-head angle, charted over weeks. Streaks get users through week one; a graph of their own neck angle straightening keeps them past month one, which is exactly where single-purpose consumer apps usually die.

Who pays

Desk workers 25-45 who self-diagnose from before-and-after content, paying $8.99/mo or $39.99/yr through a hard paywall after the onboarding photo assessment — the GoTall pricing shape. Distribution: ASO on posture terms (high volume, weak incumbents) plus short-form before/after and posture-check content on TikTok and Reels, a format that already goes viral organically for creators.

MVP scope

• Onboarding quiz with pose-scored side-profile photo and hard paywall
• Hourly micro-correction notifications with 15-60 second guided exercise cards
• Streak system tied to daily completion
• Weekly photo capture with alignment ghost, on-device angle scoring, progress chart with rolling average
• RevenueCat subscriptions with trial
• Skip for v1: Android, live webcam slouch detection, Apple Watch, social features, HealthKit sync

Build Upright Streak, a posture habit coach for iOS. Stack: React Native with Expo, RevenueCat for subscriptions, on-device pose detection via Apple Vision framework pose estimation (through an Expo native module).

Core flow: onboarding quiz (desk hours, neck or back pain, a guided side-profile photo the app scores for forward-head angle and rounded shoulders using on-device pose landmarks) ending in a personalized-plan reveal and hard paywall. Daily loop: hourly micro-correction notifications during user-set work hours (chin tuck, shoulder roll, 40-second wall angel), each one a 15-60 second guided card the user checks off; completing any correction that day extends the streak. Weekly loop: a prompted side-profile photo, shot against the same setup using an on-screen alignment ghost of last week's silhouette; the app computes craniovertebral angle from ear-shoulder-hip landmarks and charts it over weeks next to the photo strip.

Non-obvious details: all pose math runs on-device — market that as photos never leaving the phone. Angle deltas week-to-week are noisy, so smooth with a 3-week rolling average and show a confidence band rather than a single line, or users churn on one bad reading.

Screens: onboarding and paywall, today (streak plus next correction), exercise player, weekly photo capture, progress (angle chart plus photo timeline), settings.

Pricing: $8.99/mo or $39.99/yr, 3-day trial, yearly pre-selected on the paywall.