Yes, both Slack and Dotcom Monitor offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Dotcom Monitor is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Dotcom Monitor Starts at $1.99/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 Dotcom Monitor includes Super Monitoring, PageCheck, WebSitePulse, DevMonitor.io, Monitis, Uptrends, SolarWinds Pingdom, Domain Monitor, Pingt.io and DTEKT.