Yes, both Slack and GoProposal offer a Free Trial.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
GoProposal is designed for Large Enterprises, Medium Business and Small Business.
The starting price of Slack begins at $2.67/Month, while pricing details for GoProposal 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 GoProposal includes PandaDoc, Offorte, Proposify, Proposable, Propoze, seProposals, ProposalPad, Fresh Proposals, Prospero and Ignition.