I'm not sure if these phones are actually in use "cellularly". Maybe in certain countries these networks are still up.

I'm more interested in your opinion on how difficult it is to develop apps for these phones now. It seems even trying to get Visual Studio 2015 running on say a Windows 7 computer itself is a challenge.

But I have a fondness for these phones, one of those sad failed paths of the past. And they're cheap now, of course bad hardware 2gbs of ram but proportional software size and needs.