How does a person, who does not have DigiDoc4, see digital signatures? Where can you check digital signatures?

If you have a card reader and ID-card then you can use Dokobit portal. Besides checking digital signatures, Dokobit portal can also be used to digitally sign documents.

DigiDoc4 can be used to open documents and check signatures also in a computer that does not have a card reader. DigiDoc4 can be installed from Install ID-software page.