Wikia
Yes, both BlueJeans Events and Slack offer a Free Trial.
BlueJeans Events is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for BlueJeans Events Starts at $499webinar whereas for Slack Starts at $2.67/Month.
Some top alternatives to BlueJeans Events includes GoToWebinar, EasyWebinar, ClickMeeting, LiveWebinar, Zoom Video Webinar, EverWebinar, enableX Webinar, WebinarJam, Cisco Webex Webinars (formerly Webex Events) and Tevent.
Some top alternatives to Slack includes Microsoft Teams, Glip, Google Chat, ChatWork, Dialog, Office Chat, imBee, Takle, SPACE Channel and Teamwork Chat.