I created a strictly confined snap for zsync however it looks like it’s one of the reserved names in the Snap Store by Canonical.
I already created a request via the Snapcraft Dashboard to release the name to me, however opening a forum post here as well to make sure this gets some 
.
The code can be found here: https://github.com/felicianotech/zsync-snap
If I can get this reserved name, that would be great and I’ll be maintaining the snap. It’s not like zsync is active anyway. The upstream repo hasn’t been touched in years.
If I can’t get the zsync name, I’ll resort to using zsync-felicianotech I guess but then I’d like to request an alias for the command/binary name.