Steve Wozniak in the early days -- with an Apple 1 board.

Apple co-founder Steve Wozniak has a warning for Apple: Watch out for the competition. 

In an interview with the German business publication Wirtschaftswoche published yesterday, Wozniak spoke on a variety of Apple-related topics, but when the conversation turned to smartphones, was openly critical.

Wozniak said that he is proud that Apple has such loyal fans, but noted that loyalty also has to be maintained and confirmed by launching great products. He continued: "In my opinion Apple is currently lagging behind in terms of features. Others have caught up with us. Samsung is a great competitor simply because they are making great products at the moment."

Wozniak is well-known gadget geek who isn't afraid to try mobile devices of all makes and brands. He remains an Apple employee and shareholder to this day, but it's nice to see him keep an open mind about which gadgets and devices he is using. 

In the interview, he also shared that he still feels Apple's current product lineup is worth waiting in line for: 

"The launch of a new Apple product is like a big important concert for me where you have to be in person. It is history. Certainly, I could order online or ask the store manager to let me in through the back door, but that wouldn't be the same. No, I want to have the same experience as any customer. But one thing is certain: I would not stand in line if Apple made lousy products."