I have an NFC dot on the doorframe and unlock my door by holding my phone up to it. It's definitely slower than using the keypad, and probably slower than getting out a key, but it's way more satisfying than either.
For things that aren't security-related like a light, you can use a writable one, and write the URL to the dot so that anyone's phone will be able to turn the light on/off from the sticker.