Jim Cramer's Surprise Phone Call From Tim Cook

Jim Cramer celebrated the 10-year anniversary of Mad Money on Thursday night, and he received a surprise on-air congratulatory phone call from "Tim in California." It was only after Cramer answered the call that he found out the caller was Apple Inc. AAPL CEO Tim Cook.

After a surprised Cramer thanked Cook for his call, the two went on to discuss the ways that Apple is changing the world.

Growth Ahead

Apple has become the biggest company in the world by dominating the smartphone market, but Cramer identified two huge potential areas of growth for Apple.

Related Link: Expert: Why Apple Watch Will Be Apple's Most Upgradeable Product

"I'm basically looking at your company as being the healthcare company of the future; I'm looking at you as being the credit card company of the future."

Cramer believes that customer demand will eventually drive "every major retailer" to accept Apple Pay.

Research Kit

Cramer praised Apple's research kit, which Cook calls a "game-changer." Cook spoke of the preliminary success of the research kit, which drew 11,000 participants for a cardiovascular disease study in 24 hours.

"To put that in perspective," Cook added, "Stanford has told us that it would have taken normally 50 medical centers an entire year to sign up that many participants."

Apple Watch Owners Living Longer?

Cramer asked Cook about Apple Watch's potential for blood pressure, diabetes and cancer-related detection and health monitoring and whether that potential is something viewers can expect to become a reality within their lifetimes.

"Oh, absolutely," Cook replied, and went on to explain how early detection and effective monitoring of health can literally add years to people's lives.

Cramer Bullish On Apple

Cramer believes that Apple has the best balance sheet in the world.

He told Cook that his mantra is "people should own Apple, not trade it."