This App is an Online Metronome, developed with React and designed with the Material-UI Framework. Tests are written with Jest and the React Testing Library.
Note: I implemented a custom version of the type(...) method from the React Testing Library, the reasoning and implementation can be found here in myUserTesting.js
It is a Progressive Web App (PWA), which means that if you open the App it caches everything it needs, so it can be used without an Internet Connection. This is especially useful on Mobile Devices, where it can also be added to your Homescreen (at least if the Mobile Browser supports this feature).