textPlus, a text messaging app that’s powered by GOGII, has just hit the App Store. textPlus lets any iPhone or iPod Touch send free text messages to any cell number by using in-app advertising to cover its costs. There is no limit on how many text messages you can send per month, it’s just a matter of getting WiFi, 3G or an Edge connection. GOGII was one of the first companies that was funded by iFund, the partnership between venture capital firm KPCB and Apple, which was announced at the Apple SDK roadmap event.

With version 2.0 of textPlus, GOGII is announcing the availability of textPlus usernames, which can effectively serve as a stand-in for a phone number, which is great for iPod Touch users. Your friends can send standard text messages to you from any phone, simply by sending a text to the shortcode 60611 that leads off with your username followed the rest of their message (so a text to me would look like “DanielBru Hi are you coming to the movie tonight?”). textPlus also supports group messaging, though someone with the app installed needs to initiate the conversation (the other participants in the chat don’t necessarily need it installed and can use regular SMS).

One of the biggest upsides to textPlus is that you can send text messages internationally at no cost at all — the one requirement, is that you have a textPlus username. And of course, with iPhone OS 3.0, and push notifications, you’ll get a notification each time someone sends you a new text message. GOGII’s goal with textPlus is to make the texting functionality much better then what Apple has already developed.

After playing with textPlus over the last few days, I can see where the success of version one came from — textPlus is very to use, and the ads don’t really get in the way. The only thing I fear is that GOGII doesn’t have any immediate plans to support picture and video messaging, which iPhone users on AT&T; recently got.

textPlus currently supports the following carriers; AT&T;, Verizon, Sprint, T-Mobile, Alltel, US Cellular, Virgin Mobile, Nextel, Boost, Cellular One, Dobson, nTelos, Cellular South, CellCom, evol, ECIT, RINA, Bluegrass, Cox, Inland Cellular, West Central Wireless, Centennial, EKN, RCC, and Immix/Pc Management.

You can get textPlus on the App Store today at no cost. [iTunes Link]