I have just finished today’s update and now several apps are gone - I wouldn’t mind for the free ones like Buycott/Happy Cow etc. But also my Navigon App is gone and thats an expensive one!
Is that normal to happen, do I just have to reinstall the apps from the Play Store?
No, it should not happen, however, Apps bought in Play Store are usually bought for lifetime and can be transferred to any device you want and reinstalled as often as you want.
Sometimes some icons vanish after an update - the shortcuts you have on the homescreens. (I find amazon apps like kindle and audible most vulnerable to this!) For me, the apps are still installed, but the shortcuts are gone and just need replacing.