Grounds for Apple Watch + iPhone

Play. Save. Share.

Grounds records a tennis session on Apple Watch, then brings its recap to your iPhone for private review and story sharing.

Grounds requires an Apple Watch paired with an iPhone to record sessions.

Estimated, not exact

Grounds estimates forehand and backhand counts for supported player profiles. Counts can miss strokes or include false positives, and Grounds intentionally undercounts rapid same-side drills. They are not coaching, medical, or exact measurements.

Unsupported player profiles still save a workout, but do not receive stroke counts.

Your session stays yours

Grounds is local-first. It has no Kaji Labs account, backend, ads, analytics, or direct social-network upload. Sessions sync from your Watch to your iPhone. When you choose to share a story, your device's share sheet sends it only to the destination you select.

Grounds can save a tennis workout, heart-rate summaries and samples, active energy, session time, and estimated stroke counts to support your session recap. Location is optional: if you allow it, Grounds captures one location at the start of a session for your private map and stories.