At the end of my last post I said the next thing might be a watch app. Here it is. It’s called Notch, it’s live on both the App Store and Google Play, and it came straight out of my own training.
Notch is a Grease the Groove timer that lives on your wrist. Raise your wrist, tap, hang or knock out your reps, tap when you’re done. The set is logged in about five seconds and you’re back to whatever you were doing.
What is Grease the Groove?
Grease the Groove (GTG) is a strength method coined by the coach Pavel Tsatsouline. Instead of grinding out a few brutal sets in one session, you do frequent, easy sets of a single movement spread across your whole day. Never to failure. Always fresh.
It’s how you go from three pull-ups to fifteen. It’s how a desk worker builds real dead hang strength without ever setting foot in a gym. You treat the movement like a skill you practice, not a workout you survive.
There’s one catch, and it’s the whole problem: you have to remember to do the sets. A pull-up bar in the doorway only works if you actually stop and use it. Mine hung there for weeks at a time while I walked underneath it, thinking about literally anything else.
Why a watch, and why me
I’m the target user. My daily plank streak and my dead hangs are exactly the kind of small, repeatable practice GTG is built for. I was tracking sets in my head, on scraps of paper, in a phone timer I had to unlock and dig through. Mostly I just forgot.
Every app I tried buried the logging behind four taps. By the time I found the right screen the moment had passed and I’d wandered off. A phone is too far away. A watch is already on your wrist, which turns out to be the entire point. The friction between “I should do a set” and “set logged” needs to be near zero, and a watch is the only place that’s true.
So I built the thing I wanted:
- Timer logging for dead hangs, planks, L-sits, any hold
- Rep logging for pull-ups, push-ups, squats
- A live countdown with haptic ticks and a buzz when you hit your hold
- Optional heart rate capture during holds
- Today’s count and your current streak right on the watch face
- A daily nudge if you haven’t logged anything yet
The history, the progression charts, and your personal bests live on the phone, where a bigger screen actually helps. Watch and phone sync in the background so you never think about it.
Built the same way as the trees
Like the Portland Heritage Trees app, Notch was built almost entirely through Claude Code. This one was harder. It’s not a single Android app, it’s a Wear OS app, a phone companion, and then a whole second port to iOS and Apple Watch, plus a landing page and the store listings.
The Apple Watch port in particular was new territory for me. Kotlin and Compose on one side, Swift and SwiftUI on the other, the same app expressed twice. Doing that solo would have been a slog. Working through it in Claude Code, it stayed a conversation: describe the screen, see it built, test it on the actual watch, fix what felt wrong.
It’s still work. I made the design calls, wore the watch around the house for weeks finding rough edges, and pushed both apps through Apple’s and Google’s review processes. But the gap between “I want a watch timer that does this” and “the watch timer exists” got a lot smaller.
The details I care about
A few things I was stubborn about:
No subscription. The core app is free forever. If you want full history, progression charts, personal bests, and unlimited exercises, that’s a one-time $4.99 Pro unlock. You buy it once and it’s yours. I’m tired of paying rent on software I use for thirty seconds a day.
Privacy by default. Your sets, your streaks, your heart rate samples all live in a local database on your own devices. No analytics SDKs, no ad networks, no tracking. Heart rate is only sampled while a hold timer is actually running.
Watch-first, on purpose. Most fitness apps treat the watch as an accessory to the phone. Notch is the opposite. The watch is where the training happens and the phone is where you go to admire the receipts.
The Code to Muscle connection
This is the most on-brand thing I’ve made. The last app got me walking. This one is literally about the daily practice this whole site is built on: showing up, doing the small thing, stacking the reps until they add up to something.
I built a tool to make my own training stickier, and now it’s out there for anyone else who’s ever hung a pull-up bar in a doorway and then ignored it.
If that’s you, Notch is for you.
Try it
Notch is free on both platforms:
👉 App Store (iPhone + Apple Watch)
👉 Google Play (Android + Wear OS)
Or start at the landing page: notch.codetomuscle.com
Tap. Hang. Tap. Then get back to your day.
Related Post
The app this one was teased at the end of:
👉 Building an App with AI: Portland Heritage Trees on
Android