Yes, both Slack and Call of Fame offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Call of Fame is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Call of Fame Starts at $75/User/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 Call of Fame includes NordPass, Saleswhale, Refract, Call Tracking, Convlo, Siro, Convin and Avoma.