This is the first in a series of blog posts that we'll be doing as part of our new App It Up project called Cool Apps Roundup. This inaugural post will cover a variety of green or environmental apps that are already out there.

In my companion blog post on Why Apps Are Green, I talked about how apps permit the use of lighter IT infrastructure like mobile phones to accomplish things we previously used to do just on PCs. Mobile phones use much less electricity than PCs, and another benefit is that they make Internet and IT readily available in developing countries.

Another way that apps can be green is because some of them do environmental things. There's a surprising array of them actually. Planet Green's 7 Best Green Apps for Mobile Phones are a good example.

The ones I like are:

• Ecorio which uses the GPS system on your phone to track your carbon footprint as you travel.
• 3rd Whale searches for green businesses near you.
• greenMeter tracks your vehicle's fuel and power efficiency.
• Carticipate is a social media app with a very clever name to connect you with people who want to carpool.
• PedNav tells you how to walk, bike or mass transit to wherever you're going and sets you up with an itinerary.
• The Locavore app offers government and NGO info on which food items are in season in your locale. It also offers Epicurious recipes for them. It doesn't have a market-finder feature specific to in-season foods, however. Too bad.
• Zerogate's MeterRead is an iPhone app in which you record your electric meter readings and it suggests ways to improve your energy efficiency. It doesn't connect up via the Internet to your smart meter. I found that one on Reuters Green apps that can save you money.

Consumer Reports' 7 free green mobile apps has some good ones as well:

• The Eco Buzz Widget, for Android, is a configurable environmental news feed.
• Eco Defense for Android is a game that pits angry plants against dastardly pollutants - for those of us with environmental passive-aggressive issues.
• Green Gas Saver is an iPhone app that emulates a vigilant back seat driver, reminding you of when you're getting reckless behind the wheel. I don't know if I want that app.
• iRecycle is Earth911's app for iPhone and Android that helps you find recycling locations for more than 240 types of materials.
• IP Thermostat is an iPhone app that controls Proliphix Internet-connected thermostats from your phone so you can save on heating and cooling bills. There are now several brands of remote control thermostats that can be controlled from the Internet.
• Schlage Link is an iPhone and Android app that controls several Schlage home devices including a module for lights, entry door locks, thermostats, and home video cameras. An example of a Schlage home device is the Schlage LiNK Wireless Keypad Entry System. It's much more expensive than a regular door lock, but then the app is free.

Here are a few more green app top picks from sundry publications:

• Treehugger's 15 Green Apps For Your New Apple iPad
• App TVs Top Ten Green Mobile Apps
• The Guardian's list of Top 10 green iPhone apps
• Rasmussen College's Six Green Mobile Apps to Reduce Your Carbon Footprint - including ecobee, vRideAlong, NoDryClean, GreenSpace Map, Locavore and Green Gas Saver.