I would like to publish my web application for free in the Google Play store (for the exposure).
All descriptions I found so far are for native apps. Is it possible to submit a HTML only app ? How would an example manifest file look and how do I sign such an app ?
You'd have to create a webview using Android Java libraries, and then display your webapp inside of that webview. Normally if you're not doing Java you'd want to do something like PhoneGap.