Android/iOS: Using an authenticator app on your phone is one of the better ways to use two factor authentication. Now, LastPass Authenticator has an even easier option, by adding support for one-button logins on many services. The feature works by showing you your six-digit authentication code on your phone, along with a green Approve or grey Deny button. You can simply tap Approve and LastPass will handle the rest in the background. This removes the need to manually copy the six digit code over to your computer in the 30 seconds or so that it shows up on your screen. The push notifications can only work on one device at a time, so make sure you set them up on the device you're going to have on you the most.
LastPass Authenticator [iTunes App Store]