I built https://runjs.app because I wanted an easy way to run JavaScript and test out ideas.
It turned out that a lot of other people wanted the same thing.
The first version was free and very basic. After getting a lot of suggestions and feedback from the people using it, I added more features and introduced a freemium pricing model.
It's important for web developers to experiment with new browser features. Browser vendors encourage this as it can help them with crushing bugs early and refining their specs.
I think Cordova is increasing in relevance. Over the last couple of years mobile devices have reached a level of performance that makes hybrid apps feel native. When you combine Cordova with Ionic you can create write-once apps that deploy to any device and have a native look and feel.
The first version was free and very basic. After getting a lot of suggestions and feedback from the people using it, I added more features and introduced a freemium pricing model.