You might also consider checking out Quantcast's BrightScript native analytics SDK for Roku. Quantcast's Measure for Roku tools will tell you the number of active users for a channel, but it will also tell you which device models are in use for your channel, plus other things such as daily usage, user retention, audience demographics and general interests (for large enough audiences). You can check out the Quantcast Roku SDK here:
https://github.com/quantcast/roku-measurementYou can read more about Quantcast Measure here:
https://www.quantcast.com/appsDisclaimer - I work for Quantcast