Yes, both Slack and Retently offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Retently is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Retently Starts at $79/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 Retently includes SurveyMonkey, SurveySparrow, Zonka Feedback, ClearlyRated, FeedbackLink, Promoter Ninja, eNPS, GrowthScore, UserSpeaks, HockeyStack Surveys, Cognito Forms and SatisMeter.