Unfortunately, in Europe (at least) these kind of solution have no legal value, since they don't use regular certificate authorities to produce the signature.
I developed Woleet Sign years ago using bitcoin to timestamp and bitcoin signatures to sign documents hashes (allowing to keep the documents private).
Woleet Sign is still online at https://sign.woleet.io
But broken 💔
Wrong. If you read the legislation on digital signatures, the key must be something the "user can control"
Most solutions use SMS and email, neither of which produces a a signature, and neither of which are under the control of the user
We believe 99% of digital signing solutions are not compliant
We understand your point though, that corporates have more trust in the perceived "legal value" of the cert authorities
We plan to address this point more eloquently as we build out
