In the past couple of years, we have covered plenty of smart door locks that can pair with your smartphone to make your life easier. You could always build your own though. The folks at Adafruit have put together a guide that show you how to build a SMS-controlled door lock. Using a Metro Mini, Lockitron Motorized Door Lock Body, and FONA 800 cell module, you can build a door lock that can be unlocked with a text message.
Let’s not forget that Lockitron locks are WiFi-enabled. You will just have to hack yours to pull this project off. All the parts and instructions are available on Adafruit.com.