Actually it is possible, anything is possible really. This idea needs to be implemented into android os itself.

We all know clicking a link on Facebook or Gmail and it opening within the app. Sure that's fine, you can even switch to a different app.

Switch back? Sometimes... Sometimes you might end up with the link closing reverting back to where one clicked the link.

Other times the app may refresh

Also being able to switch between different parts from within any given app, and flick through multitasking within not just every app, but multiple interfaces within any specific app

It wouldn't be hard to have an option to allow x number of tabs for any given app, or every app.

5 tabs within Facebook so you can check out a post, but you also want to check market place and you seen a video you liked but clicked a link on Facebook and you click back but the very thing you were looking at after you watched that clip vanishes as your timeline goes refresh.

5 tabs maybe 10 per app would be great even