The grand launch of T-Mobile's G1 today included the rollouts of Ecorio and ShopSavvy, two applications expected be among of hundreds or more that might eventually populate Android Marketplace, Google's answer to Apple's App Store.

NEW YORK, NY (BetaNews) - During a product expo following this morning's presentation by Google, T-Mobile, and HTC, T-Mobile senior manager for product development Mitch Lustig pointed to Android's open source development platform as one big reason for the new device's appeal.

In an interview with BetaNews, Lustig estimated that when the G1 phone hits the US market on October 22, the number of applications available on Android Marketplace -- some of them free of charge -- will be roughly equivalent to 180, the same number of applications entered into the first round of the Google Challenge developer's contest. A second round of the Google Challenge is now under way, he said.

Speaking with BetaNews in their booth, developers from Ecorio credited $275,000 won by their company in the Google Challenge -- along with Google's openness to ports of applications developed for Android -- as spurring the completion of their application.

Ecorio's app takes advantage of the G1's "GPS in the background" to let users track their daily travels, plan the most efficient routes -- whether by walking or driving, for instance -- and record their own "carbon footprints" to see what kinds of personal impacts they are making on the environment.

Ecorio also plans to migrate its app to other environments, such as Apple's iPhone and RIM's Blackberry, BetaNews was told.

On the other hand, a company known as "Big in Japan" -- the producers of the ShopSavvy app -- were drawn to the Android platform by the "flexibility" of the focal point on the G1's 3 megapixel camera, said Alexander Muse, the company's "Social Ninja."

The ShopSavvy app is designed to work with Google's search functionality to read bar codes on products such as boxes of software, and then conduct price comparisons among online sites and brick-and-mortar retail stores. For the retail outlets, ShopSavvy provides street locations, in addition to pinpointing the stores on Google Maps, said Muse.