You hold the cadence. Build the intervals, and Peg drives your smart trainer through them.
The Rønnestad above is one 30/15 — thirteen reps, three sets, done. Peg sends the next target a second early, so thirty seconds hard is thirty seconds hard.
Target, seconds left, power, cadence. Big enough to read from the drops.
The plan you actually rode — one white silhouette on black. Nothing on it you'd want to crop out.
There's no account, so there's nothing to leave the phone. One tap to Strava when you want it, .fit for everything else.