Windows 8/2012 Windows Store Service crack
Imagine you want to deploy self-signed (may be repacked) appx.
You run powershell :

Then you switch to metro start screen and attempt to launch application

Whoops ! Error. This is probably because windows do not allow sideloading of metro applications.
I assume you are smart guy and made the appx right, signed it and imported code signing cert into local machine's Trusted Root certificate store.
Also you set the following policy key :
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Appx]
"AllowAllTrustedApps"=dword:00000001
Now let's start Windows Store cracking service.

To monitor cracking service activity launch DbgView from sysinternals

Let's deploy our appx again

Here is DbgView output

Now launch application again

It worked now ! This is because cracking service fakes Windows Store service to think that it is running on domain joined machine.
Microsoft allows sideloading either on domain machines or on machines having special sideloading product key installed.
May be once those keys will be available to public, but now here is my solution to the problem.
Also machines having developer license are allowed to run unsigned metro applications. But this license expires every month and
Microsoft promises to monitor developers activity to fight piracy and other abuse.
Enjoy !