If installing a smart lock has been on your to-do list for awhile, the brand new third generation August Smart Lock Pro is $50 off for Cyber Monday. This lock allows you to, obviously, control lock or unlock your door via your smartphone or Alexa. But when it really comes in handy is when you want to let in a pet sitter or overnight guest. Just send a temporary key to their phone, they’ll be able to enter, and you’ll get a notification when they use it.