Does ioS7 work for the iPhone 4?

I have an iPhone 4 and was just wondering if they get the software update.

As long as you have an Iphone 4, 4S 5 5C, 5S then you can download it. Keep in mind though if you have below 10GB on your phone it won't work to download, because it takes up 3GB of space.

Yes.

iOS 7 is available on September 18 for the iPhone 5, 4S and 4 as a free update.

It works but missing some features such as siri, airdrop etc.