Yes, both Slack and UseResponse offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
UseResponse is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for UseResponse Starts at $1,490/Year.
Some top alternatives to Slack includes Microsoft Teams, Glip, Google Chat, ChatWork, Dialog, Office Chat, imBee, Takle, SPACE Channel and Teamwork Chat.
Some top alternatives to UseResponse includes Zoho Desk, Zendesk Support, ManageEngine ServiceDesk Plus, Freshservice, Freshdesk, ClickDesk, Deskero, Teamwork Desk, LiveAgent, Support Hub, HelpDesk, SysAid, Jitbit Helpdesk, UseDesk, LabiDesk and Little SaaS Communication.