You can edit the WMAppManfiest.xml file using XML Editor. Add Extensions
after the Token
element. And Insert extension of Photos_Extra_Hub
into extensions.
<Extensions>
<Extension ExtensionName="Photos_Extra_Hub"
ConsumerID="{5B04B775-356B-4AA0-AAF8-6491FFEA5632}"
TaskID="_default" />
</Extensions>
So your app will appear on the Photo Hub Apps. If you want to edit your picture by your app in WP8. You can read Extending the photo edit picker for Windows Phone 8