Go to the Google Play Store
Tap the Download Bookshelf button to be taken to the Bookshelf download page in the Google Play App Store.
Tap the Install button and tap the Accept button. You may be prompted to sign in with your Google Account.
For Assistance with your Google Account please the Google Account Recovery Page.
Once Bookshelf has been installed on your Android Phone or Tablet, tap on the Bookshelf icon to launch Bookshelf. Sign in with your Bookshelf ID and password.