Apple CEO Tim Cook delivers the keynote address during a special event on September 10, 2019 in the Steve Jobs Theater on Apple's Cupertino, California campus.

The hearing, which focused on Amazon , Facebook , and Google , and at times Apple , also indicates that lawmakers continue to lump big technology antitrust concerns together, despite the fact that the companies operate different marketplaces and face different allegations of anti-competitive behavior.

The hearing, held by the House Antitrust Subcommittee, is another signal that Washington lawmakers are increasingly scrutinizing big technology companies over power that might not always harm consumers, but can hurt smaller businesses.

Technology executives said that Apple's App Store platform has too much power in a congressional hearing in Boulder, Colorado on Friday.

For Apple, the entrepreneurs focused on Apple's App Store, which is the only way for most people to install software on an iPhone.

Basecamp founder David Heinemeier Hansson said that anyone who submits applications to the App Store is worried that Apple could reject their app, and that the company's system of appeals is difficult to navigate.

"Every application maker using the App Store lives in fear that their application is denied," Hansson said.

He continued: "All it takes is being assigned the wrong clerk, then you'll be stuck in an appeals process that would make Kafka blush."

Hansson was referring to Franz Kafka's novel "The Trial," which describes a frustrating, mysterious bureaucracy.

Hansson also criticized Apple's practice of taking 30% of total sales processed through the App Store as "outrageous" and said his company had designed its apps to avoid it.

"We created the App Store with two goals in mind: that it be a safe and trusted place for customers to discover and download apps, and a great business opportunity for all developers," Apple said. "We continually work with developers and take their feedback on how to help protect user privacy while also providing the tools developers need to make the best app experiences."

Apple employees review every single app and update that are distributed through the App Store, CNBC previously reported, and some reviewers said that the process and rejections can be arbitrary.

Developers who disagree with an App Review decision, which is made based on Apple's App Store guidelines, can appeal to a board called the App Review Board, CNBC reported, which can change a lower level reviewer's decision. It is partially composed of reviewers with good track records, people familiar with the process previously told CNBC.

Last year, Apple published published a new webpage that explains the principles that govern the App Store as well as the most common reasons for rejection.