It's easy to install if you already have a C-wire available at the thermostat, otherwise it can be a real pain in the ass. The C-wire is basically what provides the thermostat power, and while they claim you technically don't need one, in my experience you'll have power/charge issues with it if you don't. If you have an older house, and/or simply had very basic thermostats previously, you probably don't have a C wire hooked up and you'll most likely need to fuck with wires at your air handler, being forced to jumper a wire to your fan connector.
I have 2 Nests, a Chamberlain Q garage opener, a Ring.com doorbell, Schlage wifi deadbolts, and Canary camera-- all hooked up through a Wink. You can then program "robots" on the Wink to do certain things like when you open your garage door, automatically unlock your door. Or if your front door is unlocked for X period of time, lock it. Cool stuff.