Starbucks will soon let you tip a barista straight from an iPhone. An update to the iOS Starbucks app, due March 19th, will allow customers in the US to tip digitally with their phones while paying for a coffee. You’re typically free to tip any amount in cash at a counter tip jar, but Starbucks is limiting digital tips to just 50 cents, $1, or $2 through the updated app.

Starbucks users can also shake their phones to pay

Starbucks' move to digital tips compliments the impressive growth of its mobile apps. More than 11 percent of all store transactions are now completed using mobile apps, and Starbucks dominates mobile payments in North America. That’s thanks in large part to the popularity of the coffeehouse chain, but also because its mobile apps are simple to use. Starbucks is even adding a shake to pay option in its latest iOS update, allowing customers to shake their handset to bring up the required barcode for mobile payment.

Although the tipping option will roll out next week, it won’t be available on every corner. While there’s around 11,000 Starbucks stores in the US, the company says tipping will only be available at 7,000 of the company-operated locations.