To access publications that you have purchased through the app you should visit Joomag's web Newsstand page and perform the actions described below.
Already signed up through the app
From the web Newsstand click Log In button
Enter the account credentials and click Log In button
Tap on your username and navigate to the My Library section to read the publications you have access to
If you are signed up with a guest account
Sign up for a reader account right from the app.
Click on the burger menu at the top right corner of the screen
Tap on the Create Account option and then enter your account credentials
To access the purchased publications with the newly signed-up account perform the steps mentioned above