I've Googled "Inbuilt" but found nothing. Do you mean builtin? When you say photos do you mean your gallery? A brief search shows that there are a lot of complaints about the S4's camera and gallery apps. I would say try restarting it, even though I'm sure it's probably restarted itself after the update. If your app doesn't return you may consider a factory reset or getting another gallery app from the Play Store.