It's been a busy few months for Nest: the company just re-opened sales after catching up with backorders for its popular Learning Thermostat, and now it's rolling out its first app updates, a new energy-saving mode, and some minor hardware tweaks as well.

The most significant update comes right in time for summer: Airwave is a new way of controlling your air conditioner that promises to save up to 30 percent in cooling costs. The idea is basically to take advantage of excess cooling capacity and cold air stored in your A/C compressor and ductwork — the Nest will stop the compressor about five minutes earlier than usual and blow out the additional cool air to bring the house down to your target temperature. "There's a lot of potential that's just wasted" in conventional A/C systems, says Nest's Maxime Veron. "We shorten your A/C cycle and just use the fan to cool your home at a much lower cost." Airwave will work with all forced-air air conditioning systems, and Veron says the Nest will monitor relative humidity levels to make sure it doesn't blow around humid air. It'll be enabled automatically after a Nest firmware update that's rolling out today.

Nest is also updating it entire suite of apps, both on the web and on mobile devices. The Android app is now fully on par with the iOS app, and both the web and mobile apps have been given a new "at a glance" settings screen and the ability to set away temperatures and enable the "range" mode that auto-switches between heating and cooling.

More importantly, the apps now feature Nest Energy History. All the apps will now show exactly how much the thermostat has been running your HVAC system for the past 10 days, display a leaf icon for days with low energy use and explain major changes in energy usage with one of three icons: being away, a user adjustment, or the ambient weather conditions. Veron says Nest owners tend to use the apps several times a week and monitor their energy use almost daily, and Energy History will allow them to "understand how the temperature choices they make impact energy usage."

The Energy History UI is pretty slick: the first screen shows you the past 10 days, with a solid bar that indicates how long the system ran on each day, as well as the leaf or energy change icons. Tap on a bar to expand it into detail view, which shows exactly when the system ran and at what temperature — Nest says the additional detail will allow users to tweak settings more finely and cut up to five percent of daily energy usage with changes as small as one degree. It's clever, although you can't actually make tweaks from within Energy History; you have to go back out to the main programming window. It's also somewhat odd that Nest isn't quantifying a percentage of energy saved or even the raw amount of time spent running the system, since that seems like something people would fight to drive lower, but Veron stressed patience. "We have to educate customers one step at a time." The apps are all updated and should be available today; Nest owners who've been running the most recent firmware will be able to view their energy history immediately.

And lastly, Nest has made two small hardware tweaks to make self-installation of the thermostat slightly easier. The backplate that mounts on the wall now features redesigned wire clips that are easier to use, and the included drywall screws no longer require anchors — Nest has developed custom dual-threaded screws that anchor themselves.

Nest has promised even more features and updates over the lifetime of its thermostat, and this is certainly a solid beginning. We'll be checking for the updated apps soon and let you know what we find.