You may test your apps directly within your browser from your app's Private Management URL. We provide in-browser iOS Simulators and Android Emulators free of charge for this purpose.
However, if you would like to test your apps on physical devices, the process differes between Android and iOS.
For Android, you may download your Android APK directly from your app's Private Management URL after building through our website. You will see a link called "Download Android APK". For iOS, please see our documentation at https://gonative.io/docs/#ios-device-testing.