There is a free demo available directly on the official Nomad Sculpt website that runs in a browser (including Safari on mobile) so you can test the tools before buying.
A single desktop license key officially covers two devices . Why "Free License Keys" are Risky
If you are looking for a completely free professional alternative for 3D sculpting, (for PC/Mac) is the industry standard and is 100% open-source.
: You can use a limited version of the software for free directly in your browser at NomadSculpt.com .