I built an interactive Flutter Web demo so people could try my fitness app before launch

Dauntra — Wed, 16 Sep 2026 17:38:08 +0000

I've been building a fitness app called DAUNTRA.

One problem I kept running into before launch was simple:

People could see screenshots of the app, but they couldn't actually use it.

I didn't want to wait until the App Store release to find out whether people understood the product, so I built a separate interactive Flutter Web demo.

What is DAUNTRA?

DAUNTRA combines:

workout tracking
nutrition tracking
progress analytics
Lab Insights, which tries to help users understand patterns in their training and nutrition data

The goal isn't just to collect more fitness data.

It's to help make that data easier to understand.

The demo

The web demo uses fictional athlete data, so you can explore the app without creating an account or entering personal information.

You can actually navigate through:

Workouts
Nutrition
Progress
Lab Insights
Profile

The demo is built separately from the production app and doesn't connect to real user data.

Tech

The main product is built with Flutter.

For the demo I used:

Flutter Web
CanvasKit
a dedicated main_demo.dart
fake/precomputed demo data
Cloudflare Pages
PostHog for anonymous product analytics

One of the more interesting problems was making something originally designed as a mobile app still feel natural when shown inside a desktop browser.

Try it

Interactive demo:

https://demo.dauntra.com

Main site:

https://dauntra.com

I'm still pre-launch, so criticism is much more useful to me than compliments.

I'd especially like feedback on:

Is the product understandable without me explaining it?
Does Lab Insights seem useful or unnecessary?
Is the web demo comfortable to use?
What would you change before releasing the actual app?

Feel free to be critical — that's exactly what I'm looking for.

DEV Community: Dauntra

I built an interactive Flutter Web demo so people could try my fitness app before launch