The World Wide Semantic Web team just made the acquisition of a smart-phone! … but it’s not any smart phone 😉
From the camera app to the mail client everything is wrote with Web technologies. There is no native code involved at any time. You may want to look at the bootstrap app code and consult this nice documentation, or that one, to get some more information. There exist two distribution channels for web apps: hosted like a web site or packaged for installation (that is, all the site content in a zip). Many of these Web Apps can already be found on the marketplace.
The main development environment for the apps is the app-manager shipped with Firefox. Just open the special page “about:app-manager” (or look into the “Web Developer” menu) in a recent (>= 26) version to try it out! It also comes with a device simulator 🙂
The APIs used within apps are being standardised by the W3C. There is a group for the Web Apps concept and the system interfaces. For example, the recommendation for the manifest file that describes the app and lists the access rights can be found as a github-hosted W3C draft. So once you coded a Web App, you’re done. Just like you are with a web site. Your Web App will run on anything that implements the W3C recommendations correctly!
I already shared a lot of links but some more interesting things are a check-in app for Foursquare (see especially the part about using OAuth2 on FFOS and the list of access rights in the manifest) and the UI guide. There are also instructions to install the OS on not supported but working devices.
Please don’t hesitate to ping me, or someone else from the WWSemWeb group, if you want to play with the phone and see how to code on it 😉