let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as! String
        let build = Bundle.main.infoDictionary?["CFBundleVersion"] as! String

пишем расширение

extension UIApplication {
    func getVersion() -> String {
        let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as! String
        let build = Bundle.main.infoDictionary?["CFBundleVersion"] as! String
        return "\(version).\(build)"
    }
}

применение

...
UIApplication.shared.getVersion()
...