How I update my iPhone 4s in iOS 9

The iPhone 4s can be updated to iOS 9.3.5. See the following for instructions: Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support

If your iPhone is running iOS 7.1.2 and will not update beyond that, you may want to verify that it isn't an iPhone 4 rather than a 4s.

You did not state what iOS version is installed on your iPhone. It can be upgraded up to iOS 9.3.5, which you need to do before those apps will be compatible.

To upgrade iOS go to Settings > General > Software Update.

ISO 8

How can i verify that it isn't iphone 4 rather than iphone 4s

Check the model number at: Settings - General - About - Model = ???

Input this number in your favourite search engine, or post back to here.