For all topics that aren’t device specific.
Not that easy to come up with a catch-all description. Calling it “General discussion” doesn’t work well since I started a subcategory “General discussion”. 
“Topics that don’t fit anywhere else” - although true - doesn’t seem very inspiring. In principle “Topics that aren’t device specific, or OS/new technology/tablet software” is more precise, but too long.
Maybe we can leave it at “Topics that aren’t device specific” for simplicity, and manually move any topics that belong in the Technology category. If it gets to be too much work we can come back and wordsmith the description. 
Edit: or alternatively, we can leave it blank. The other top level categories don’t have a description either, and the subcategories kind of speak for themselves.