If it shows me the raw data—sets, reps, weight, heart rate, recovery time—then it’s useful. If it’s a cluttered UI with pie charts and motivational quotes, ditch it. Just numbers, a clear trend line, maybe a simple warning if the data dips. Keep it updated in real time, no lag. That’s the kind of thing that keeps me in the zone. If you’re going to build it, make sure the graphs are high resolution, the colors distinguish progress from regress, and there’s a quick way to log a new session without interrupting the flow. That’s how you stay on track.