The ZADA App is a Digital ID Wallet that enables your to manage your digital credentials. You can receive new ones and you can share the ones you have.
Yes, anyone can use the app but only approved issuers can provide you with credentials to store, and only approved verifiers can request data from you.
COVIDPass is a standardised credential for proving a COVID-19 vaccination or test done. It is stored in the ZADA App after being issued by an approved health provider.