Apple and other retailers around the world are training their staff with the latest iOS 7 mobile operating system. as Apple gears up for its iPhone 5S/6/5C media event on Sept. 10.

Although the iOS 7 was introduced in June at the WWDC event this year, the official version has not yet been seeded to retailers. With six beta versions released until then, thousands of developers are waiting for the Gold Master version, which will be the last and final version offered to developers prior to public release.

In preparation for the upcoming iOS 7 release, slated for next week after the launch of the new iPhones and new iPad, app publishers have begun updating their apps for iOS compatibility.

EA, one of Apple store's largest publishers, has updated Real Racing 3 with "full support for the latest version of iOS," according to GottaBeMobile.

Apple will launch the iPhone 5s/6/5c for a possible Sept. 20 release date. If that is the case, the iOS 7 is expected to roll out to existing iPhone owners some time between Sept. 10 to Sept. 20. However, iPad owners are likely to receive an update some time in October after it is rolled out to handsets first.

Apple finally confirmed the date of its keynote event by sending out a colorful invitation to selected media on Sept. 4 – a week before the event. The invitation is decorated with colorful bright dots with the infamous Apple logo in the middle with a message that simply reads, "This should brighten everyone's day."

For the first time, the Cupertino based company is expected to launch a budget iPhone - dubbed iPhone 5C/6 - in a variety of colors. By the look of the colors on the invite, Apple may launch the phones in yellow, blue, red, orange and purple as well.