Hide or not to hide the system tray in a Windows Phone 7 application?

Transparency and colors are now possible with Mango by setting its BackgroundColor and Opacity :

shell:SystemTray.IsVisible="True"
shell:SystemTray.BackgroundColor="Transparent"
shell:SystemTray.Opacity="0"

I would say by default show it unless it really gets in the way in a way you can't workaround, especially if its an app and not a game.

Loading Data when the User Scrolls to the End of a List in Windows Phone 7

http://danielvaughan.orpius.com/post/Scroll-Based-Data-Loading-in-Windows-Phone-7.aspx

Windows store app Installation : Purchse Error

While Installing an app from Windows store i got an error : 

"Purchase Error"

while reading some of the msdn forums and trying multiple solution the following one is helped to install app from the store.

install the following tool it will automatically fix the issues related to store.

This troubleshooter automatically fixes some issues that might prevent your apps from running, including suboptimal screen resolution and incorrect security or account settings.

http://download.microsoft.com/download/F/2/4/F24D0C03-4181-4E5B-A23B-5C3A6B5974E3/apps.diagcab

Ref : http://answers.microsoft.com/en-us/windows/forum/windows_8-windows_store/anybody-knows-how-to-fix-windows-store-error-code/481ae2ae-b8cc-427a-9154-0ac8587b6f88

Thread.Sleep replacement in .NET for Windows Store

Thread.Sleep doesn't seem to be supported in .NET for Windows Store apps.

For example, this

            System.Threading.Thread.Sleep(1000);

Windows Store apps embrace asynchrony - and an "asynchronous pause" is provided by Task.Delay. So within an asynchronous method, you'd write:

await Task.Delay(TimeSpan.FromSeconds(30));

... or whatever delay you want. The asynchronous method will continue 30 seconds later, but the thread will not be blocked, just as for all await expressions.

How can I autoplay a video using the new embed code style for Youtube?

I think if you use replace "&" with "?" in the url the video will autoload.

So your url would be: http://www.youtube.com/embed/Tfy5CBfjZ8s?autoplay=1

Seems like Google should have made this available, but I would say using a "?" makes more sense than using the "&".

How to make a control in XAML as public in order to be seen in other classes

 x:Name="myCheckBox" x:FieldModifier="public" />

Windows Phone 8 SDK installation information 

Either way you have to download the SDK, either online installation file here: http://dev.windowsphone.com/en-us/downloadsdk

Or complete offline installation ISO here:
http://go.microsoft.com/fwlink/?LinkID=257234&clcid=0x409