Marketing Channel Manager and Marketing Channel Processing Rules are applicable and valid for all the Report Suites irrespective of your platforms(Website or Mobile Application or any OTTs).
But do you think you can build conditions the same way as the Website if it is a Mobile Application? Guess cannot.
For the Website, we usually use Query String Parameter but not sure we can do that for Mobile Application. So, for Mobile Application, the conditions/logic will change but still Marketing Channel Manager and Marketing Channel Processing Rule can process it without any issues if you have processable conditions.
You can use Marketing channel processing rules for setting Marketing Channel Reports for mobile app based report suites. These reports are independent of Ptaform ( App or website) and are run based on marketing channel processing rules configured within Report Suite Manager ( Admin> Report Suite> Edit Settings> Marketing Channel> Marketing Channel Processing Rules )
The Marketing Channels will work on the basis of your Marketing Channel Processing Rules, you can use the same Marketing Channel Processing for the Mobile Report suite that you are using for your Website report suite if you think those conditions which you have defined will be matching the condition for your channels. Otherwise, tweak the Marketing Channel Processing rules if the hits are not getting attributed to the correct channel's based on your requirement.