Microsoft’s Windows Mobile platform may have more than 20,000 applications developed for it overall, but when the company launches its own mobile app store this Fall, it says there will be roughly 600 certified and available.

The number is far less than Apple’s 50,000-plus, and also falls below Google’s Android, which has around 5,000, but is much more than the Palm (NSDQ: PALM) Pre, which hovers around 30. Microsoft’s figure was reported by MobiFrance, which interviewed Audrey Zolghadr, Windows Mobile Product Manager at Microsoft (NSDQ: MSFT) France (via wmpoweruser.com). In a translated version of the text, she said Windows Marketplace for Mobile will allow people to either buy applications on their credit card or through their operator bill. They will also be able to return the apps within 24 hours if they are not completely satisfied. In addition, she said Microsoft wants to make the smartphone more “fun,” and will offer some new games for free. Microsoft has signed a partnership with EA Games, so that the handset manufacturers can integrate such games as “Sim City.”

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