All of this is trivial to figure out from the provided command line. As a matter of fact, I did just that to verify it was possible and it took about 3 mins (which was what one would expect given that command line) to get the file, untar it, and look at the build script and the other build script it references. Since anyone downloading this tool likely wants it, 3 mins is fine.
That second build script includes more non-SSL fun if you feel like playing that game.
So I should clutter my home directory with stuff that may or may not break if I later try to move it somewhere sensible?
> ... && ./install.sh
Then I let it programatically dig its tentacles into who-knows-what, making uninstallation laborious and/or dangerous?
Why not give a hyperlink to some "qira.tar.xz" file, and have it execute from the resulting directory? Such applications are usually easier to package too, making it more likely to appear in repos.