If you have purchased your subscription or single issue via the Google Play Store, signing into the app is not necessary. Your purchases should automatically be displayed via your Google Play Account Log on. For purchase troubleshooting please see here.
If you received sign in credentials from the publisher, sign in your account:
- From the Menu Icon > go to "Sign In"
- Tap on "Print Subscriber"
- Fill in your email and password and tap on "sign in"