I built an Apple Watch app that tracks your heart rate for every set — launching today, AMA

Hey everyone 👋,

I'm Karthik, a solo developer from India, and Iron Karnet goes live on Product Hunt in about an hour.

Every workout tracker tells you what you did — sets, reps, volume. None of them tell you what your body was doing during it. So I built a Watch-first lifting tracker where your Apple Watch streams heart rate through every single set. You can see which exercises actually push you hardest, how fast you recover between sets, and whether your conditioning is improving week over week — not just whether the numbers on the bar went up.

It also handles supplement schedules and water logging from the wrist, so the phone stays in your gym bag.
If you apple watch supports gesture ( double tap) .

Solo stack, for the curious: SwiftUI, HealthKit, WatchConnectivity, StoreKit 2, Firebase. Happy to go as deep as anyone wants on the build — the per-set HR correlation was a genuinely hard problem and I have opinions now 😄

🎁 Launch offer for the PH community: free week, then 3 months at $4.99 → [redemption link]

Question for the lifters here: what's the one thing your current workout tracker doesn't tell you that you wish it did? Genuinely asking — the roadmap is wide open and I'd rather build what people want.