Safe Exam Browser for macOS and iOS
Open SafeExamBrowser.xcodeproj in a recent version of Xcode (currently 12.5). For building you have to switch off code signing or add your own code signing identities. SEB uses the com.apple.developer.edu-assessment-mode entitlement, which needs to be requested from Apple for your developer team.
Currently master reflects SEB for macOS 2.3.2. The latest iOS version of SEB was developed in branch 3.0_iOS. The last iOS version (2.1.17) still compatible with iOS 9.3.5 is archived in branch 2.1.17_iOS.
The new unified macOS/iOS/iPadOS Xcode project (Xcode workspace with both macOS and iOS targets) is being developed in branch 3.0_unified.
All information about Safe Exam Browser you'll find at http://safeexambrowser.org, especially see https://safeexambrowser.org/developer/overview.html. Other documentation is available in the according repositories. Search discussions boards if you don't find information in the manual and SEB How To document (see links on page Support).
For your information: The correct way how to spell SEB for user-facing text is all three letters in CAPS. If you find SEB written as seb in code, then that's ok if it's some symbol users will never see. If you find SEB written as Seb, then that is definitely WRONG.