From Security InfoWatch: a survey of locksets currently on the market that can be operated from mobile devices, including products from Kwikset, Goji, Lockitron, and Viking Electronics. From the article:
"A new class of keyless residential locks is emerging. Wireless technology now allows a user to unlock their door by either just touching the face of the door lock or through no physical action at all, except to have a programmed fob or smartphone in pocket or purse. As the user comes in close proximity to the door, a wireless signal automatically alerts the lock to unlock."
Here's a video review of the Kwikset Kevo lock from CNET, according to which it was priced at $219 in the US at the time it was first released (October, 2013).
Prices of these products will come down over time as smartphone market penetration increases, and vendors find it more worthwhile to offer keyless systems. But they won't replace good old metal locks and keys any time soon. Why? People lose their devices. Batteries die. And someone might decide to jam the Bluetooth network, or hack the lockset system itself. So while smartphone based locksets are decidedly cool, they will, at best, be supplemental to good old metal locks and keys, at least for the foreseeable future. Note that all of the locksets reviewed still have slots for physical keys.