http://mediacomcc.custhelp.com/app/answers/detail/a_id/794/~/tv-everywhere#what
Looks like you need Google Play or Apple Store to download it. And you need to have their highest tier (in the CR market anyway) to receive Marquee. It appears you can have unlimited number of devices, but simultaneous streamers are limited (and of course they don't tell you how many in the FAQ's).
HOWEVER...they don't exactly give you a TV Anywhere channel lineup. Looking in the FAQ's, they state "not all channels on your TV package are available to stream".
You may have to call them to find out. And oh yeah - it figures that MC would not tell you these answers online.
Just found this...I don't believe you'll be able to.
What is the Marquee Sports Network App and TV Everywhere?
The Marquee Sports Network App and TV Everywhere is a live and on-demand sports content mobile App and desktop experience designed for iOS, Android and other devices, such as Apple TV, Fire TV and Roku with internet access.
The App will include live streaming of all Marquee Sports Network programming, including live Chicago Cubs games for users who authenticate using their provider credentials and reside in the Cubs broadcast territory (per MLB rules). On-Demand videos and Cubs-related content will be available.
https://www.marqueesportsnetwork.com/faqs/