Yes, both ReplyManager and Desku offer a Free Trial.
ReplyManager is designed for Large Enterprises, Medium Business and Small Business.
Desku is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for ReplyManager Starts at $39/Month when Billed Yearly whereas for Desku Starts at $19/User/Month when Billed Yearly.
Some top alternatives to ReplyManager includes Zendesk Support, Zoho Desk, Tidio Helpdesk, Freshservice, Freshdesk, Teamwork Desk, LiveAgent, HelpDesk, SysAid, Jitbit Helpdesk, eStreamDesk, EngageBay Helpdesk System, EvantoDesk, HelpdeskEddy, LabiDesk and BoldDesk.
Some top alternatives to Desku includes Zendesk Support, Zoho Desk, Tidio Helpdesk, Freshservice, MessageDesk, Freshdesk, LiveAgent, HelpDesk, SysAid, Jitbit Helpdesk, eStreamDesk, UseDesk, HelpdeskEddy, Desk360, BoldDesk and Alerty.