Arrowpointe Maps is currently in the process of getting certified, which should be completed in the next couple weeks. Once certified, it will be listed publicly on the AppExchange.
Until then, Unlimited, Enterprise, Developer & Platform Edition orgs can install Arrowpointe Maps from the AppExchange by clicking on the image below. Once it is certified and publicly listed, it will be available to Professional Edition customers too. If you install Arrowpointe Maps in your org, you will get a free 15-day, 5-user trial with full functionality.