This app is very useful, but the trouble is that when I select which app or apps they all disappear and depending on which apps are floating my notes for my online class automatically are deleted and the app itself disappears along with my notes, then sometimes the app will reappear again. I had to stay up real late last night because those notes I made for myself... cost me a few test grades. If this information helps I'll tell you what I was doing while the floating app where hovering:

Browser that I was using with the floating apps was the "Puffin browser" and occasionally Google

The website that I was on was Apex (where I go online to finish tests and notes for my Geometry class) through bcps one.

"Hovernote" hovering over my screen as well. 

My tablet is an HP 10 tablet (old tablet).