Made it Progressive

Well, I wanted to make the app installable and finally did it - now the app is PWA short for Progressive Web App. This way when loaded from a mobile device it would request to install it on the phone.

The benefits of this - more look and feel as native app on the phone, which also it should have persistent storage (not wiped out by clear cache).

The persistent storage is not so critical especially if the user sync it with his personal cloud account (Dropbox or Google Drive), but still nice to have.

On a side note - still struggling to drive traffic to it...