An update is currently being deployed (as usual First Release tenant first) to let you pin your Apps from the App Launcher directly to the navigation bar
To do so, just open the App Launcher and right click (or click on the ellipsis …) to get the contextual menu and choose More\Pin to nav bar
Off course you can do the other way around, unpinning from the navigation bar after you have pinned an application; the steps are exactly the same except you will to choose Unpin from the nav bar 
