According to some reports online, Apple is set to release an iPhone 8 and refresh/updates to the iPhone 7. Some reports claim that a larger screen format is coming with the refresh.

As well there are reports that iOS 11, a long anticipated release will also be available around the same time.

No specific dates, but most likely the second or third week of September.

If you want to take a look at iOS 11 beta, which is currently on beta 4 for public release you can register at beta.apple.com, be sure to do this with a second phone, not your primary phone as this is pre-release and has bugs.