From an iPhone/iPad:
You can sign-up to Bazaart using a Google/Facebook/Apple account. Go to Settings > Sign Up > choose your preferred identification method. The sign-up method chosen will give you access to the Bazaart Web App.
From an Android mobile:
Currently signing up on an Android device is not possible, but we are working on it.
From the Website:
A signup process is necessary when purchasing a premium subscription on the web. If you're not sure which identification method you used check your inbox (Email subject: Welcome to Bazaart Premium). If you are still experiencing issues please contact Support using the "Contact Us" button in the Bazaart Settings.