Slack offers Free Trial, but Awesome Screenshot does not.
Slack is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Awesome Screenshot is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for Slack Starts at $2.67/Month whereas for Awesome Screenshot Starts at $2/User/Month.
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 Awesome Screenshot includes ScreenshotsCloud, Urlbox, Screenshot Machine, Screenshotlayer, ScreenshotAPI, FireShot, Snapup, Screenlapse, Droplr and ScreenshotOne.