All Zendesk, Gorgias, Re:amaze, Kustomer, and Onsite Support account levels are compatible with ChannelReply.
ChannelReply is compatible with all paid plans for Freshdesk (Growth and above).
With Zoho Desk, ChannelReply is compatible with the Standard plan and above.
Help Scout users need the Standard plan or above to use ChannelReply. Help Scout Plus and Company accounts have the added feature of being able to use ChannelReply data in Custom Fields.