has any seen an S6 Edge sport armband ?
If you search "Galaxy S6 armband" in ebay or amazon, there are quite a few. Some say "S6/S6 Edge", which makes sense. I imagine the armband will work for both, since they don't need to be any different in that case.
I have one of those cheap ones that you can get for under $5 in a range of colours for my S3, it's still working well years later.