When you think about it, the experience of making a phone call hasn’t changed very much over the years, even as the devices we use to make those calls have undergone a revolution.

“It’s crazy,” says Rob Williams, CEO of Sidecar. “But the calling experience really hasn’t changed much since the days when phones were still plugged into the wall.

"At Sidecar, we are reimagining the phone call for the age of smartphones, because you should be able to take advantage of all of the features of your smartphone when talking on it.”

What that means, first and foremost, is being able to share things.

Sidecar’s free app, which has just launched today for both iOS and androiddevices, introduces a capability the company calls “smart calling,” that allows people to share video, photos, contact info, and location data while they talk.

“No one else out there is doing ’call and share,’” Williams says. “Services like Tango or Skype are really just literal extensions of the traditional phone call that add in video.

“Whereas we have tightly integrated sharing into the calling experience. You can be talking back and forth, when -- at a certain point we call the ‘hand wave moment’ -- you start trying to describe what’s around you.

“You might be at a loss for words. You pull the phone away from your ear and with Sidecar, it automatically goes on speaker mode based on moving away from your ear.”

What happens next is you see four options as buttons on your screen: See What I See Video (SWIS), Photos, Locations (on a map), and Contacts.

There also is something called “whisper text,” which allows users at noisy locations, like concerts, to continue the conversation via texting while the phone is away from their ear.

Signing up for Sidecar is easy; your phone number is your ID. Calls to other Sidecar users are free anywhere in the world, just as with Skype, and Sidecar users can use Wi-Fi to call any number in the U.S. or Canada for free as well.

The company is split between two offices, with a team of six in Soma, and four more in Seattle.

Williams co-founded the company with his long-time colleague Rob Glaser, best known for RealNetworks, and Jeff McLeman of BeSquared.