Yes, both Slack and Flodesk offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Flodesk is designed for Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Flodesk Starts at $24/month when 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 Flodesk includes Campaigner, Moosend, SMTP, ActiveCampaign, Omnisend, Klaviyo, Constant Contact, MailChimp, Campaign Monitor, GetResponse, Systeme.io, MailerLite, AWeber, ConvertKit, Square Marketing and SendFox.