Plank King's leaderboard runs on Game Center, so it needs two separate permissions turned on before anything shows up: one inside the app, one on your iPhone. Miss either and the leaderboard stays inaccessible.
Once it's connected, the ranking compares your longest planks against other users worldwide — the same stat the app already tracks for you locally, just made competitive.
Steps and screenshots verified against app version: 26.4.27
1Turn on the Game Center switch in the app's settings
The app is explicit about this: "You need to turn on the game center switch in the app settings, and enable the game center authorization in the phone settings to use the leaderboard." Start with the switch inside Plank King's own settings.
2Enable Game Center authorization in iPhone Settings
The app-level switch alone isn't enough — the system also needs to authorize Game Center for Plank King, as the same instruction says. Grant that in your iPhone's Settings, then come back to the app.
3Confirm the sync succeeded
You should see "Sync Game Center succeeds!". If you get "Sync to Game Center Error" instead, double-check both switches from the previous two steps — that error means one of them isn't actually on yet.
4Complete a session the normal way — not by manual add
For a score to reach the leaderboard, it has to come from a real session — timer or sensor detection. The app is explicit about the one exception: "Note: Manually added data won't sync to the leaderboard!"
5Open the leaderboard and check your rank
From the Leaderboard section, you can now see how your longest plank stacks up against other players worldwide, updated automatically every time an auto-detected session beats your record.
The leaderboard stays live as long as both switches stay on. Turn off Game Center later and you lose access to it — the app says so plainly: "You will not be able to use the leaderboard after closing the game center."