You can sign in using your email address, Facebook, or Google account. The guide page, including the map, is accessible through your mobile or computer browser. Additionally, offline access is available via the Rexby app!
By downloading the Rexby app and buying my guide, you can download your itinerary for offline usage. Soon you will also be able to download the whole map in the app. However, if you are using a web browser, an internet connection is required.