Yes, both Slack and FastField offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
FastField is designed for Individuals, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for FastField Starts at $23/user/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 FastField includes Cognito Forms, Formsite, Typeform, MightyForms, 123FormBuilder, stepFORM, Microsoft Forms, GoCanvas, Jotform Mobile Forms, Forms.io by 500apps, FormLink and Formee.