Because Open Web Apps are a work in progress and are not yet standardized, you will have to install a pre-release version of Firefox to be able to use them. For Android you need Firefox Aurora for Android (as of September 2012). Aurora is pre-beta software.
Open Web Apps for Android
- put it here: https://developer.mozilla.org/en-US/docs/Apps/Apps_for_Android
Android is one of many platforms that can run Open Web Apps.
What you need
If you want your Open Web App to run on an Android device, the device needs to have Firefox Aurora for Android at this time (September 2012). Aurora is pre-beta software.
There are no other special needs for developing Web apps for Android, other than keeping in mind that it is a small-screen device, and it can provide access to device APIs that are not available on a desktop OS.
If you want your app to run well on Android, keep in mind that a smartphone is a small-screen device and this must be handled properly by your app if you want the app to be usable. There can be device APIs available on a smartphone that are not available on a desktop OS. For example, orientation, geolocation, vibration, and so on.
The general apps developer documentation on the Mozilla Developer Network applies to apps that you want to develop for Android.
If you are developing apps for the Firefox OS and do not yet have a Firefox OS device, testing the app on an Android phone can be helpful.
A best practice for doing this is to use responsive Web design. [link http://en.wikipedia.org/wiki/Responsive_Web_Design]