How to include an app in Common Apps using feed.json:

You will need direct links for both x64 and x86 variants (if x64 or x86 is unavailable, just use other one)
Official app title
A tag, usually the app title - without spaces - preceded by a 'c'
A PNG image - needs to be up to 256x256, should not exceed 50kb in size and must be with transparent background
The group in which the app will be included to

Available groups:

{ "Title": "Google Chrome", "Link": "<link_x86>", "Link64": "<link_x64>" "Tag":"cChrome", "Image": "<link_to_png>", "Group": "Internet" }