As announced on our blog, tomorrow we're launching an Channel Progression to all Channels on Mixer on our Desktop Platform. Other platforms such as our Apps will get support for this feature in coming weeks.
As detailed in our blog, Channel Progression lets users who watch Mixer Channels earn hearts to rank up in the channel they are watching. If you'd like to tap into this feature as a developer then please take a look at our documentation page here.
If you have further questions please send us an email.