This is a continuation of the thread "iOS 10.3 beta: springboard sees no more apps..." in the now archived iOS 10.3 beta forum.
It describes a seemingly rare problem starting with iOS 10.3 / AFPS transition, where the iOS device will randomly "forget" all or most of the installed apps. Leaving the springboard to display the few remaining apps along with home screen bookmarks - these don't seem to be affected. When it happens, the info section of the settings will show no or a low one digit number of apps as well. However no memory is released, so the apps don't seem to actually be deleted. Making this look more like some sort of database of plist corruption.
The one common thing about the few users (three known to me, including myself..) having reported this seems to be a large number of installed apps >1.000. And verly likely as well a long history of migrating the installation over many iOS updates adding apps over years.
I have now also had one incidence of this occuring on iOS 11 GM, which I had been running for about a week at that point.
Now on 11.2.6. Still not fixed..