Apple Watch apps get installed, used twice, then forgotten. Fifteen that survive that test — each one solves a specific wrist- friendly problem.

Health & fitness (5)

1. Strong (workout logger) — quick set logging on the wrist.
2. AutoSleep — sleep tracking without wearing the watch to bed required.
3. HeartWatch — heart-rate patterns; flags anomalies.
4. WaterMinder — hydration tracking.
5. Streaks — habit tracking with watch-face complication.

Productivity (4)

6. Fantastical — today's calendar on the wrist.
7. Things 3 — tasks, with quick "mark done" from the watch.
8. Drafts — voice-to-text capture, syncs to Mac/iPhone.
9. Timery (for Toggl users) — quick time tracking.

Daily-life (3)

10. Apple Maps — wrist-navigation for walks and cycling.
11. Shazam — one-tap song identification.
12. Carrot Weather — at-a-glance forecasts.

Messaging / communication (2)

13. Slack — quick triage of DMs without opening your phone.
14. Messages (built-in) — reply via dictation or scribble.

Payments (1)

15. Apple Pay (built-in) — the feature that justifies the watch alone for many people.

Fifteen is a lot. Install five — one from each category. The Apple Watch only pays back when the apps on it are the ones you genuinely use in the patterns the watch format supports (glance, tap, done).