Cachly updates like any iPhone app. On your phone and usually on your phone's first screen of icons is a blue icon labeled App Store. Click the App Store icon and once opened click Updates in the bottom right of the screen.
If you are configured to auto update, there are probably no apps showing that need to be updated as your phone does it for you behinds the scenes. If you are set to manual updates, each app will have an Update button listed and you just click Update for each app.
You might have already been updated to the latest version depending on your phone settings.
I hope that helps.
