Yes, both Slack and Breeze offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Breeze is designed for Large Enterprises and Medium Business.
Pricing for Slack Starts at $2.67/Month whereas for Breeze Starts at $10/user/month when monthly.
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 Breeze includes Quickbase , Smartsheet, ClickUp, Zoho Projects, Wrike, Teamwork, ProjectManager.com, ProProfs Project, Microsoft Project, Streamtime, GoalStream, WirTask, Quick Base, Height, Flow and Project Insight.