Yes, both Slack and KORI offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
KORI is designed for and undefined.
The starting price of Slack begins at $2.67/Month, while pricing details for KORI are unavailable.
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 KORI includes ZoomInfo SalesOS and ZoomInfo.