Yes, both Slack and Gtmhub offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Gtmhub is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Gtmhub Starts at $1/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 Gtmhub includes Synergita, Ally, Weekdone, OKRs.app, Ahundred, Workboard, SugarOKR, Datalligence OKR, Kazoo OKR, Peoplebox, JOP and SmartOKR.