Yes, both Slack and CrowdPower offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
CrowdPower is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for CrowdPower Starts at $48/Month when Billed Yearly.
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 CrowdPower includes Customer.io, SimpleCRM, Parlor, ClientSuccess, Custify, Segment, Ortto, Freshdesk Customer Success (Formely Freshsuccess), Engage.so and Smartarget.