Yes, both Slack and Justworks Hours offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Justworks Hours is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Justworks Hours Starts at $4/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 Justworks Hours includes My Hours, Hubstaff, Timesheets.com, Clockify, Timeero, TimeTrack, Timesheet, Timet, Time Tracker by eBillity and Open Time Clock.