Similar in concept to Adobe Reader, Power BI should have a Power BI Viewer so when a Dashboard is shared, the sharee does not have to go into the tool itself.
There is a viewer app, you can get it here: https://powerbi.microsoft.com/en-us/documentation/powerbi-mobile-get-the-windows-app/ But you would still have to login to your account. Not sure if that is what you meant.
