Why don't some apps show up in Task manager, app history?

I only have a few examples of this, but Mozilla firefox is a big one. I am currently typing this forum post in the application, while at the same time I have the task manager up on the app history tab. Firefox is no where to be seen. I think the only apps that show up there, are Metro apps... Is this true, and if it is, is there a way around it?

I see it under processes, but not under app history.. I am guess that is because it is not a metro app..

Yes only Metro Apps are showing in app History

Wrong. See last item of the "Options" menu. It will show all applications in the app history tab.

thanks for the tip! didn't know about this.