Rad Mobility

Since turning 40, I’ve found myself wanting more dynamic stretching and mobility work in my routine, and the hard part has been getting started. Once you’re in a yoga class, the friction to doing yoga is pretty much gone… it’s getting to the class that’s difficult. Working out at home is the same for me. The friction is all in the setup: opening an app (often youtube), searching, scrolling, wondering if this one is too long or too slow, and ten minutes later I’m watching something that has nothing to do with stretching.

So I built Rad Mobility, a tiny app that picks the video for me. When I open it there’s one routine ready to go and all I have to do is press play. If I’m not feeling it, I can tap “Show me another” and it swaps in a different one.

Morning / Evening.

Here’s how it works:

• It opens to a single video from a creator I like, always between 5 and 16 minutes long. There’s no search bar, no sidebar and nothing recommended next, so when I finish the stretch I can get on with my day.
• It changes with the time of day. Before 6 pm it shows higher-energy movement, the kind that wakes you up, and after 6 pm it switches to slower wind-down mobility. The whole screen shifts from sunrise to night to match.
• A thumbs up shows me a routine more often, and a thumbs down removes it for good.
• A row of dots tracks the days I’ve stretched this week, and finishing a video gets a little burst of confetti.

And what it’s built with:

• A single web page written in plain HTML, CSS and JavaScript, with no framework and no build step
• A hand-picked list of about 70 YouTube videos, which is just a text file I can add to or trim whenever I like
• YouTube’s own embedded player to play the videos
• The browser’s local storage to remember my thumbs up and down and the days I’ve stretched, so there are no accounts and no backend
• Saved to my phone’s home screen so it opens like an app
• Hosted on this site, which runs on Railway
• Claude Code, which wrote all of it

The build itself was the easy part. The first working version came together in under an hour late one night, and I spent about two more hours the next morning getting the look and feel right, so roughly three hours in all.

If you want to try it, it’s at michaelrad.me/mobility.