August has put together a nice “bolt on” smart lock for existing deadbolts locks. Through their app you can create revokable virtual keys for guests, house cleaners, etc that can allow access on a certain schedule. You can see my full review here and find one here at the best price (affiliate link). These go on sale from time to time and I’ve seen it sold as low as $179.
I reviewed the prior model in this product line and this new one definitely feels more refined. It’s more compact, has better battery longevity, and integrates Wi-Fi in addition to Bluetooth for connectivity. It supports the “big three” (Apple Homekit, Google Home and Amazon Alexa) but the Wi-Fi connectivity doesn’t work with Apple Homekit. So you’ll need an Apple device like an Apple TV or an old iPad within Bluetooth range to access the lock remotely.
What I like the most about the August products are the virtual keys you can assign to users. These keys are revokable, meaning you can delete them without having to call a locksmith, and you can set them to be valid only during certain days or times of the week. Guests accessing the home will need a smartphone (iPhone or Android) running the August app, however.
The lock also comes with a sensor that will detect when your door is ajar or open.
While most of the door locks I’ve reviewed run on AA batteries this one runs with an odd size – it requires two CR123 lithium batteries. Battery life will depend on whether or not you’re using the Wi-Fi and how often the lock is triggered to open and close.
I did have to use the included trim piece (the black circle you can see behind the silver lock) because the lock was so small that it didn’t fully cover the hole cut for my deadbolt lock.
If you’re looking to make an existing dumb deadbolt smart this is a good solution. You can keep your physical keys for yourself and share virtual keys for those you want to grant access to your home.