Meditate is a free and open source web app that allows you to time your meditations. It's simple to use, works offline and aims to be the perfect aide for your meditation practice!
You can find the source code here.
If you have any ideas, feedback or bugs you can raise them here.
If you like this then you might also like Webnotes, another web app I built that lets you create and manage notes.
I hope you enjoy the app 🙂