December 2010

Volume 25 Number 12

Editor’s Note - Windows Phone 7 App-roval

By Keith Ward | December 2010

Keith WardA quick glance at this magazine’s cover reveals that our theme is Windows Phone 7 application development. In this space a few months ago, I listed some factors that will be important in selling your app (, and in this issue, David Platt’s Don’t Get Me Started column (p. 92) has more good advice.

But I think it’s time to hear from a developer who’s actually built an app for Windows Phone 7. Bob Baker wrote his first PC statistics application in 1978. Since then, he’s worked in a lot of different areas of development, including some “Silverlight insider work,” as he calls it, back in the day. Currently, he’s working as a contractor at a Fortune 50 company. Suffice it to say that he’d be recognized as an expert witness if this were a court case.

Baker’s also a musician who plays bass and guitar. It’s only natural, then, that his first Windows Phone 7 app is a metronome: he calls it “MetroGnome,” as it’s gnome-themed. It’s his first-ever mobile app on any device, so Baker didn’t know exactly what to expect.

Overall, Baker says that developing the app wasn’t particularly difficult because he has a deep Silverlight background. The first version of MetroGnome, in fact, took only about 12 hours of development time. “It’s all .NET,” Baker says. “The general accessibility of writing something on this platform is miles ahead of Windows Mobile 6 and 5 ... That model of building something with the whole infrastructure is in place.” One thing Baker says he would like to have, though, is OS access.

Baker also pointed out a few other areas he’d like to see Microsoft improve upon. And it starts with better documentation. “The documents are pretty thin. Most of what I’ve learned is the result of pinging [Microsoft support], finding blog posts, sample code,” Baker says. He adds: “I wish [Microsoft had] spent more time tying together app submission guidelines and UI guidelines. There aren’t a lot of helpful samples, at all,” from Microsoft.

The next set of challenges for Baker came when he submitted his app for Microsoft approval. He says he submitted MetroGnome for approval on Oct. 18. After nearly a week of waiting, he found out his app failed the approval process. The problem was that he didn’t know why the app failed. The application-publishing site—or “App Hub,” as it’s called—didn’t tell him why the app failed. A PDF was supposed to give him information on why the failure occurred, but the document was blank, Baker says.

“Meanwhile, I didn’t know if it was something wrong with my code—or something else,” he explains. Baker e-mailed support, and eventually got a return PDF that said there was a screenshot failure. The explanation for the failure, according to Baker, was that he didn’t take a screenshot of the running application. There was no other explanation—and the one he received was an unhelpful one at that, as he included screenshots with his submission.

Ultimately, the issue turned out to be a quirk in how a screenshot is captured. “I spent four to six hours banging my head against the App Hub, trying to get it to do what I wanted to do—checking forums, sending e-mail to support, etc.,” he says. It turns out that doing a “region capture” screenshot results in the inclusion of a border from the phone emulator he used. Those added pixels meant that Baker’s screenshot was too small, causing the failure. “There’s a whole bunch of people who ran into the same thing,” he says. (As one developer said []: “The screenshot can be taken from an emulator, but can’t show the emulator.”) After resubmitting the app with the new “window capture” screenshots, the app sailed through the approval process in less than a day.

In all, Baker says he’d give the current Microsoft Windows Phone 7 submission/approval process a “B-minus ... There are lots of bugs in the App Hub system. I hope they get it fixed.” He also says that he realizes this is brand-new territory for Microsoft, and is overall happy with the process. In fact, he enjoys mobile development enough now that he’s working on his next Windows Phone 7 app: a tuner for musical instruments.

What have your efforts to build a Windows Phone 7 app been like? Let me know at