One of the biggest launching events of Apple is happening this coming September 9. To stay on the top, the multinational company competes with other growing rival companies, including itself.

In a market statistics posted by The Wall Street Journal, Apple had the slowest year-over-year rise in terms of its unit sales for their iPhones. If the slow sales continues, the company will experience the biggest drop of sales for the first time compared last year.

Apple then must provide an excellent new features to their newest iPhones in order for the company to get back to the first place. While it's not yet official, pattern shows that the company will be upgrading its latest iPhone 6 to iPhone 6S and iPhone 6S Plus.

If Apple can pull this together, the company will be able to have a large unit sales in the fourth quarter of fiscal 2015 which will have the largest revenue effect in the first quarter of the fiscal 2016.

Rumors and speculations have been circulating stating that the new devices will present more improved performance and capacity like a triple increase in the battery performance, improved quality in the cameras, additional features for Siri and more.

The iPhone is considered as the centrepiece of Apple's business. According to an analyst named Ian Fogg, 69 percent of Apple's total revenue (that is roughly equivalent to $123 billion) is coming from iPhone.

Although the company is also releasing an updated iPad and iPad Mini, and Apple TV, it's not comparable to what iPhone can contribute in the total sales, thus making the device a critical piece for Apple's future.

For the past years, Apple is having larger and stronger group of competitors. One of the company that they are competing with is Google, which is known for its own Android operating system and other internet services. Samsung is also one of their consistent rivals. In the first three months of 2015, the company has contributed 82.4 million smartphone shipments compared to Apple's 61.2 million units.

However, experts say that the greatest rival of the company is not Samsung or Google, but its own self. Every time the tech giant releases new models of iPhones, the older versions automatically becomes obsolete and people no longer crave for them. Thus affecting the sales of the company.