If you're using an OverDrive account, Facebook, or your library card
You can sign into the OverDrive app on up to six different devices (Android, Chromebook, iOS, or Windows 8 and up) at a time using an OverDrive account, Facebook, or your library card. This also authorizes the device to download Adobe (DRM-protected) eBooks and allows you to sync your progress and bookmarks between devices. Visit this help article for help managing saved devices.
If you're using an Adobe ID
Adobe allows you to activate up to six devices using the same Adobe ID. If you've reached the activation limit for your account, contact Adobe Customer Service and ask them to reset your Adobe ID.