I personally think that most people just use an ordinary 3d program like 3ds or maya 
A good software is: ://www.makehuman.org/
Is fuse popular among developers?
I dont know if it’s popular, but I like fuse, because it’s easy to use
Good point, thanks for the input
From my experience, most devs like to model from scratch. To them, it’s easier to create from scratch than to mod a model from a tool.
Even though I’m just a beginner and consider myself as one of the biggest newbies around, I too prefer to build stuff from scratch.
Best way to learn after all 
I use Fuse, because it is great for generating characters for prototyping. If I ever get beyond that stage, I will make better ones with specialist software, but I’m concentrating on UE4 at the moment.