I wrote a PWA to help reduce meat consumption. It's a fairly simple app - you install it, and for every plant-based meal, you get one 'meat coin'. For every meal with meat, you use one 'meat coin'. A meal with dairy costs half a meat coin.
All data is stored locally in your browser*. There's no log in, no cloud server, no syncing, no analytics, no nothing, just nice big buttons for you to press.
Check it out at mtc.joeinn.es
Interesting stuff I used:
- IndexedDB (super simple with jakearchibald's key/val wrapper)
- FitText.js (the adactio version so I don't need to use jQuery)
* this also includes the sandboxed browser PWAs run in.