What is the Apple Developer Program?
The Apple Developer Program is Apple's paid membership for publishing apps. It costs 99 USD a year, or the local equivalent, and gives access to the App Store, TestFlight, App Store Connect and services such as push notifications, iCloud, Sign in with Apple and In-App Purchase. Individuals and organizations can join.
More about Apple Developer Program
You don't need it to build an app or to run it on your own iPhone: a free Apple ID can sign apps for your own device. Nonprofits, accredited educational institutions and government entities can ask Apple for a fee waiver.
Apple Developer Program with Borel
With Borel you can build apps and on Pro keep them on your own iPhone with Borel Companion and a free Apple ID. When you want an app on the App Store, you join the Developer Program, connect it in Borel's publish flow on the Pro plan, and Borel builds, signs and uploads the app for you.
Related terms
Make your iPhone app in Borel
Describe it in your own words. Borel writes it in Swift, builds it on its own Mac and puts it on your iPhone.