Microsoft group program manager for the Windows 8 Developer Platform Ian LeGrow has explained that the Windows 8 app development program was designed for non developers. He outlined the process of creating and submitting an app at an event in The Netherlands.
According to LeGrow there are important consistent elements to all Metro style apps: Metro style tiled design, fast and navigation, support for multiple states and devices, and support for the right Charms, or navigational elements. The good news however - according to LeGrow at least - is that Microsoft will do three quarters of this work for you. He said that an app that is mere stable fast, and easy to use is merely a three-star application, and one that is beautifully designed, and functionally complete just four stars. But he stressed that using Microsoft's Dev Center this work would be largely done for would-be developers. The tricky part, he said, is to 'delight and capture imagination'. And on that devs are on their own.
Developing Windows 8 apps - Where to start
That's the easiest bit: head over to the Dev Center, at dev.windows.com. Here you'll find the Metro Style Apps Dashboard, which is the key entry point for developers. You can create an app as a project, reserving its name. You'll also find tutorials telling you how to code Windows 8 apps, and code samples. LeGrow demonstrated this by searching for the term 'Geo-location' - he found code samples in multiple languages, commented with advice. So you can use the language you already have to adapt the code. There are more than 500 such samples in multiple languages, LeGrow said.
At the Dev Center you can also download the Windows 8 RP and useful tools in which to code your app. There is a Support tab, as well as Community, and the Windows Runtime Component allows multiple languages to work together in the same app.
Without writing a single line of code, you can preview a basic app with no content, and then tweak from there. As you code you can see a live preview - hovering over code in Visual Studio let's you see how your app appears while it is still running, or you can simulate the app in a small window, running the app as you code it, adjusting the screen size to see how it looks on different screen sizes, and in different aspect ratios. Here you can also take multiple screenshots of apps in development in order to aid the design process.
Baked in functions require only a single line of code - you simple add in the code for 'Share' to add social and email options, for instance. To improve the design you can visually change application in VisualBasic Blend - a tool that has an interface like a DTP program. HTML taken from a website renders in the app - so If your syndicated HTML includes video tags, you don't need to 'add' video capability to your app, Windows 8 will work it out. And video automatically streams out to Xbox - controlled from Windows device - with zero code required (like 'Share').
Apps run on Windows RT devices, as well as X86 Windows 8.
Once you have a working app, you head back to the Dev Center to create an app package and submit it to the Windows Store. Microsoft will run content checks, and technical checks before deciding whether to list your app, but LeGrow said this was a 'transparent process that gives users confidence that apps are going to be great'. To help this process you can run the Windows App Certification Kit, which LeGrow claimed is the same tool run by Microsoft for pre-Store technical checks. If your app passes your own test, it is going to pass the code check, he said. And if it fails before you submit, you get immediate feedback.
Once you have an app that has passed you add an age rating, name, cryptography, and notes to testers, and then wait for your app to appear in the Store.