Why does my Mail App for Office show in Outlook online but not in my installed Outlook Client?

I have developed a mail app for office.

It is showing in my Office 365 Outlook in my browser but not in my installed client.

On the web

But in my installed client it looks like this. Ie the app is not showing:

In the client

I have looked at managing apps etc but can't find any settings to force it to show in my installed client.

Any ideas?

Here is my manifest:

Manfest

Please note, this is not a real app but more of a "trying things out" app.

ok so here is my version of Office: enter image description here

And here is my updated manifest file as @andrews requested I remove the regex rules to simplify trouble shooting:

enter image description here

I un-installed the app, restarted everything and I still cant see it in my Outlook desktop client.

thanks Russ

Solution

your manifest is version 1.1, but your Outlook build is not 2013 SP1. Outlook 2013 SP1 builds are 15.0.4569 and higher. Please update your Outlook client, and then the app will appear!