In order to expand the subscriber base with large OTT devices list you need two main tools - management system and multiplatform player.
We use our own management system
Telebreeze Middleware, a full-featured tool for managing IPTV/OTT business. Through the Middleware a service provider manages content and subscribers, DRM, monetization services, statistics, subscribers' personal areas.
Telebreeze
Multiplatform Player supports all the most popular users platforms: Smart TVs, set-top-boxes, mobile devices, PC, media players — Roku, Amazon FireTV.