People love to hate on the Apple Watch. But I think I may have stumbled on the killer app — using it to track how often I pee.

Why would I want to log my pees?

To remind myself to drink more water. That’s the concept behind my app, Pee & See. I just released the Apple Watch app as part of version 1.1 this week.

Quick Pee & See History

I knew I wasn’t drinking enough water. Sometimes I would get terrible headaches as a result. This killed productivity, and made me feel unhealthy.

Tracking water intake was too annoying. I had a different idea: tap a button every time I pee, then get a reminder when it had been a while.

I made a pee tracking website in late 2014 (just for me). It was clunky to load a website every time I peed, but after using it for a year I was drinking wayyyyy more water and feeling great.

I built Pee & See as an iOS app in early 2016 to make it faster for me and accessible to more people. Then I found the ultimate platform for Pee & See…

Perfect for Apple Watch

Why is this a perfect app for the Apple Watch?

It’s useful independent of the iPhone app

The Complication makes interaction faster and better

See how long it’s been since you peed without even trying.

Complication

The focal point of Pee & See for Apple Watch is the Complication.

It’s a perfect low-friction way to gain awareness of how much time has passed since you last peed. If the number is getting high, it’s an automatic, passive reminder to drink water.

It just shows up when glancing at the time.

On the iPhone version of Pee & See, you get a notification if it’s been 3 hours since you’ve peed. With the Complication, you don’t always have to wait for a notification to remind you to drink water.

The Complication has another important feature: it launches the app.

The Complication instantly launches the app, then it’s just one more tap to log a pee.

Watch App

In my testing, it takes less than 5 seconds of interaction with the Apple Watch log a pee.

Tapping the Complication instantly opens the app. One more tap on the Log Pee button is all it takes. There's a subtle vibration to confirm the pee has been logged.

The app doesn’t scroll, so the button is in the same predictable place every time for quick, consistent logging.

This type of two-tap, several-second interaction seems to make an app the perfect Apple Watch candidate.

Depending on how well Touch ID feels like working on my iPhone, the process of logging on the iOS app takes 5–10 seconds. That’s at least 2x the time it takes on the Apple Watch, plus I can leave my phone in my pocket. For adopting a new habit like this every second counts.

Time Travel

The Complication normally shows how log much time has passed since your most recent pee.

With a quick spin of the Digital Crown, Time Travel will give a quick idea of how often you’ve been peeing over the course of the past day.

There’s an animation to emphasize each pee that’s passed as you scroll.

This is a fast and anecdotal way to interact with historical data. I’m sure there could be better ways to visualize the data over time with graphics on an iOS app counterpart, but this lightweight interaction provides a quick summary.