SEATTLE, 2015-4-17 — /EPR Retail News/ — Today, April 15, 2015 Starbucks is expanding the digital tipping feature to customers using Starbucks® mobile apps in Canada. This feature allows customers to show their appreciation to store partners (baristas) by leaving a tip through the Starbucks® app for iPhone® or the Starbucks® app for Android™. After completing a transaction…