Walter Isaacson, author of the best-selling biography "Steve Jobs", told CNBC in an interview that Google is currently the world's greatest innovator and Apple needs to do something big to regain its charm.

Walter Isaacson wrote the bestselling biography of Steve Jobs and had access to insider information than any outsider can only dream of. Isaacson believes Google is more innovative than Apple, and something like this coming from the man who knows the inside story of Apple is quite alarming to Apple fans.

He also noted that the Apple-China Mobile deal was a big win for the Cupertino tech giant, but Google's Nest acquisition was more important.

Apple secured a deal with China Mobile, the biggest wireless carrier in the world, in December. The deal was a big win for Apple the carrier avoided the iPhone lineup for several years, even after competitors like China Telecom and China Unicom offered them. Apple hopes to push its iPhone sales in the Chinese market, which has been dominated by Google's Android-based smartphones like the ones from Samsung, Huawei and Lenovo.

"The Nest labs is popular for its sensor-driven, Wi-Fi enabled, self-learning, programmable thermostats and smoke detectors, which represent the "amazingly strong integrated strategy that Google has to connect all of our devices, all of our lives, from our car, to our navigation system, to how our garage doors are going to open," Isaacson said in an interview with CNBC.

As a part of the deal, Nest co-founder and CEO Tony Fadell will be moved to Google in the company's future endeavors. "The greatest innovation today is coming from Google," Isaacson stressed. "Fadell was one of the team that created the iPod. He was very deep into the Apple culture ... when Apple was so innovative ... Now Tony Fadell is going to Google because he's part of the Nest deal ..."

According to the well-known author, Apple must do something really big to win over the  innovation-loving fans. CEO Tim Cook has often spoken about "big plans" for 2014 and it is time the company gets in the game to turn things around.

Speculations have that Apple may be readying a larger screen iPhone, larger iPad, Thunderbolt 4K display, a smart TV, or a smartwatch, for its so-called secretive "big plans."