Ask HN: Easiest way to make a mobile app into a website?

We are growing company that develops clinical decision support mobile software. We have chosen the mobile first route. We are now getting requests to make our software available on browsers. Is there any easy way to make an iOS or Windows 8 app into a website? The iOS app is native and the windows 8 was built using (xaml, C#). I am aware of systems such as app.io, however I am not sure this would work for day-to-day use. We are looking for something that would give us an end product like this - https://carmacarpool.com/desktop/. I am sure a lot of mobile first companies have this problem so there maybe an opportunity here??