Swing With Me — An AI Stroke Coach in Your Pocket
A native iOS app that records your tennis strokes, compares them frame-by-frame to a pro's form, and delivers the coaching feedback most players can't afford.
A native iOS app that records your tennis strokes, compares them frame-by-frame to a pro's form, and delivers the coaching feedback most players can't afford.
Tennis improvement requires real-time, specific feedback from someone watching you. Without a coach, you keep reverting to the same bad habits. I designed an app that does what a coach does: breaks down where your form differs from a pro's, stroke by stroke.
I interviewed recreational tennis players across skill levels and ran a competitive analysis across 6 existing apps. The biggest finding was about audience, not features.
Beginners needed foundational instruction first. Intermediate players had specific, named problems. I pivoted to intermediate players, which simplified every subsequent design decision.
Paper prototyping came first. Every screen started as a sketch before any pixel work.
The design evolved through four distinct fidelity stages. This slide captures the full progression.
The hi-fi prototype moved from stick figures to real tennis footage, real player comparisons, and a dark-themed UI designed for on-court readability.
The core screen: YOUR footage compared frame-by-frame to Djokovic's. Visual cues highlight form differences. Verbal cues explain what to fix. The Follow Through screen delivers specific coaching text.
The AI feedback results were designed as a black box. Participants wanted to understand the reasoning behind their score, not just see the gap. A second iteration would focus entirely on the annotation and scoring explanation layer.