Latch is a leading vendor of internet-of-things "smart" doorlocks that are in increasing use in rental housing (the company claims 10% of all new multiunit construction incorporates their product); they allow entry by keycode, keycard, and Bluetooth.
Latch's privacy policy is the usual IoT dumpster fire, allowing the company to harvest a vast amount of information from you and also share that information with a wide array of third parties, including (sometimes) your landlord.
Almost every method of unlocking your Latch requires an app in the loop (even PINs that you use with a numeric keyboard are delivered by app) and the app gathers huge amounts of information on you. Moreover, landlords can choose to configure Latch locks to require the app. more