Icons bouncing or jittery

If you are looking at your app in GRID view (versus LIST view) and you softly tap and hold one of the icons, then you put yourself in "re-arrange" mode (not the official term I am sure) which allows you to re-arrange and delete apps. This is similar behavior to moving apps around on the iPhone or iPad

For what it is worth, I find using LIST view much more user friendly. If you press "hard" while viewing your apps you can toggle between the two views.

You may have reseted your finger on an icon a bit too long. That causes the icons to "wiggle" and gives you the opportunity to remove an App. To stop the "wiggling" just press in the crown.