Mountain View, California (CNN) -- Meet Evernote CEO Phil Libin, who runs a software company based here in Silicon Valley that has been on a hot streak.
Last month, the company launched an iPhone application, called Evernote Food, that lets users keep track of favorite recipes and restaurants. It was an instant hit.
Evernote also released an iPad app, called Skitch, for drawing and annotating on images. It has skyrocketed from 200,000 to 5 million users since Evernote acquired the startup behind the technology in August.
All of Evernote's apps tie into its online note-taking and file-storage service. It has 21 million users, of which nearly a million pay for access to more storage space and capabilities, Libin said.
The company's major growth left executives scurrying for a place to fit all of its new employees. They will move into a much larger headquarters in nearby Redwood City, California, in the next few months, Libin said.
"We want to be the Zynga of getting stuff done," Libin told CNN, referring to the maker of such hit social-network games as "FarmVille" and "Words with Friends." "I think that's really what we're becoming."
Despite the successes, Evernote's most ambitious recent project hasn't immediately taken off.
Evernote Hello, a quirky iPhone app for exchanging contact information that launched at the same time as the Food app, has not gotten off to a terrific start. It's billed as a replacement for business cards and address books, asking users to hand their phones over to strangers who then input their e-mail addresses and phone numbers and snap head shots to help them pair a face with the name.
CNET, the CBS-owned technology website, covered it under the headline, "Evernote Hello shares cooties and contacts." Another tech blog, ReadWriteWeb, called it "an app only Sheldon Cooper would love," a reference to the fictional nerd from the CBS show "The Big Bang Theory."
Libin, who does bear some resemblance to the TV character played by actor Jim Parsons, said Evernote is making changes in response to user feedback.
For example, the app should allow users to snap a picture of a business card using the iPhone's camera and automatically input the information from it -- like LinkedIn's CardMunch, Libin said. It may also let two people who have the app running exchange contact info wirelessly in a process similar to the Bump app, he said.
Users will also have the option of inputting the data themselves manually, rather than handing the phone over to a new acquaintance, Libin said. However, he defended his original concept, saying that people take better pictures of themselves when they are controlling the camera.
"Your photo booth instincts kick in," Libin said. "You just get better photos. But whatever."
During an interview at Evernote's headquarters last week, I handed Libin my phone and asked him to input his contact information into the Hello app. He winced and observed that the app has already advanced so far beyond the publicly available version I was using that it was barely recognizable to him.
Libin describes the alphabetical organization of most contact lists as outdated, a remnant from when people's names and numbers were printed on linear pages. Perhaps the last mainstream innovation in address books came in 2007 when Apple introduced a favorites list to the iPhone.
Evernote Hello shows contacts in a mosaic of people's faces. "Your brain doesn't remember things alphabetically," Libin said.
A new version of Evernote Hello will be available in the next few weeks, Libin said. It should bring the product closer to Libin's original concept of supplanting the address book by giving it a 21st-century update and merging it with your calendar.
"It's sort of as if your address book, your calendar and your camera had a love child," Libin said. Part of the inspiration for Evernote Hello came from Libin's own inability to remember people by name, he said.
Still, the app has a long way to go. As Libin tweaks his pet project, Evernote developers are working on at least two more apps to be released this year. One is for keeping a to-do list, and another is for organizing travel tips, Libin said.
"Hello is really ambitious, and it's going to take us a long time to get it right," Libin said. "But it's the one I think has the most potential to change things."