The Volvo On Call app will let you lock and unlock your XC40 and what's really interesting is the option to unlock and start the car remotely so your family can drive it too. Don't think I'd personally go for it because I fear some technology changes when it comes to security.
https://play.google.com/store/apps/details?id=se.volvo.vcc&hl=en
https://play.google.com/store/apps/details?id=se.volvo.vcc&hl=en