A few months after launching a developer toolkit for writing apps that run on wearable devices, Salesforce.com says the concept is gaining traction with customers and partners. The initiative, which is called Wear, launched with a number of hardware partners, including Google, Philips, Samsung and Fitbit. Now Epson, Jawbone, Meta, Oculus and Vuzix have joined the party, Salesforce.com said in an announcement Thursday.