This Nest competitor will surely be a part of the HomeKit API
Alongside iOS 8, Apple will release development tools to control home appliances, the newest will be the Lyric, a smart thermostat that will compete against the Google-owned Nest, the current leader in this particular market. This will offer all of the same features that the Nest will, including being able to remotely control the climate with your iDevice and adjust temperatures according to schedules if necessary. It is different in that it can change the temperature according to things like indoor and outdoor humidity, temperature, and even the weather. This is something that Nest isn’t capable of.
Apple currently sells Nest through their retail stores, despite being owned by Google, although they are expected to be moving towards Lyric, which is produced by Honeywell, one of their team for the HomeKit API. The Lyric from Honeywell will retail for $279 when it goes on sale this coming August. It is possible to purchase it from some contractors, however, and they have put together a list of those that they are using to distribute it.