For SXSW Marketers, Smartphone Apps Are Yesterday's News. Wearables Are What Matter

But brands are waiting for critical mass

If Roberto Moctezuma was trying to launch a mobile startup just a few years ago, he'd only have to think about use cases involving iPhones and Samsung Galaxies. But as he demonstrates his three-month-old app called ThereThere at South by Southwest this weekend, everyone wants to know how it will work on Apple Watch, Samsung Gear and other wearable devices.