Yes, both Slack and Fastbase offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Fastbase is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Fastbase Starts at $39/Month.
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 Fastbase includes Whoisvisiting, Leady, Visual Visitor Sales Intelligence, LeadMagic, ipstack, Dynamic Leads, Lead Revealer, Websitez, VisitorAPI and LeadRebel.