A lightweight enum based Feature flag system

FeatureFlag.swift

enum FeatureFlag: String, CaseIterable {
    case featureOne
}
extension FeatureFlag {
    var isEnabled: Bool {
        switch self {
        case .featureOne:
            if isRunningInAppStore() {
                return false
            }
            return featureFlagValue()
        }
    }
    private var key: String {
        return "com.companyname.featureflag." + rawValue
    }
    private func featureFlagValue() -> Bool {
        return UserDefaults.standard.bool(forKey: key)
    }
    func enable() {
        UserDefaults.standard.set(true, forKey: key)
    }
    func disable() {
        UserDefaults.standard.set(false, forKey: key)
    }
}