(Free) Video conferencing is a crucial feature for many businesses. If everyone on your team has bought into a service like Skype or Slack, then you're all set. But what about those times when you're talking to people outside your core team? Appear.in is a great solution because it doesn't require any registration or setup whatsoever. Just create a room and begin inviting people to it via email, Slack, or your platform of choice. All the recipient has to do is follow the link to join the call. You can share your screen and add up to four people to the call for free. To add up to 12 people, you'll have to pay $9.99/month for a Pro account.