The idea for Seattle startup Apptentive started as a conversation on a 16-hour road trip as co-founders Robi Ganguly and Andrew Wooster drove from the Bay Area to Seattle.

Wooster had several apps in Apple's App Store during that time in 2008, and Ganguly pestered him with questions about who his customers were and how much they liked the apps. Far too often, the answer to those questions was: "Apple doesn't really enable you to do that," or "It's hard to see who the customers are."

Two years after that fateful drive, Ganguly, Wooster and two other co-founders started Apptentive, with the goal of making it easier for app owners to understand and interact with their customers.

Apptentive develops ways for app owners to talk to their customers and get feedback within the app, without making people visit an outside site. Apptentive can create in-app surveys for users to give feedback on features, and lets companies encourage users to leave positive reviews of the app.

The has been focused on since it launched. But "our customers started asking 'could you do this for the web?'?" said Ganguly, who is CEO. So the startup is developing tools for companies to interact with customers on as well as mobile.

Apptentive generally helps large companies that have more than a million people using their apps. Its customers include Zillow, Concur and OfferUp.

The company has raised more than $12 million from investors, including Origin Ventures, SurveyMonkey and Vulcan Capital last year.

Apptentive has grown from 28 employees at the beginning of the year to 40 now, a fast clip that has Ganguly focusing a lot of energy on hiring.

"Most of my life is interviewing or meetings with the team," he said.

The company, based in downtown Seattle, will likely have more than 50 employees by the end of the year, Ganguly said.