Don't use this library. Better option: https://www.b4x.com/android/forum/threads/b4x-xui-swiftbutton.95180/ This is a wrapper for https://github.com/TakeScoop/SwiftyButton. The PressableButton should be added as a custom view with the designer. The open source project is a Swift project. This is the first library that wraps a Swift project. The wrapper code is available here: https://github.com/AnywhereSoftware/B4i_iSwiftyButton You should also copy the framework to the Mac Libs folder if you are using a local builder. Note that there is no simulator binary included in the framework. The minimum version for Swift libraries is iOS 8: Code: #MinVersion: 8 Edit: v1.01 is released. Fixes a small issue. The framework is available here: Xcode 9: www.b4x.com/b4i/files/SwiftyButton.framework.zip Xcode 10: www.b4x.com/b4i/files/Xcode10SwiftFrameworks.zip You should download it directly to your Mac.