Many iPhone X/8/7/6 users after updating to iOS10 or iOS11 are facing issue with apps icon visibility on home screen. After successfully installing the apps the user finds that all of apps (except for the pre-loaded ones) are not on the home screen. They are surely on the iPhone as they are shown in settings, and you can search them from spotlight search, but the "icon buttons" are not on the home screen of iPhone. The issue is quite annoying as Phone apps are missing but marked "installed" in App Store.
There are few workaround to fix “downloaded app but no icon iphone” issue as listed below:
Fix 1: Reset Home screen layout
You can refresh your home screen in iPhone to get back all the icons. In iOS11 Goto->settings->General->Reset->RestHomeScreenLayout. It will rearrange all your apps and take away all your folders but your apps should be visible. Once you have done this the missing app icon may start to appear again.
Fix 2: Remove restriction
Check Setting -> General -> Restrictions. If restrictions are enabled for the App Store, it's icon is removed and you cannot install apps on the phone. Eg If you have it set to anything 12+ and lower YouTube will be restricted. You’ll need to set it too 17+ to be able to launch it again.
Fix 3: Use iTunes to load the icon
Connect the iphone to computer and open iTunes app. Once iTunes detect your phone, scroll through the device's homescreens via iTunes and see if you can locate the app. If not, do an iTunes backup. Afterwards, see if the app is listed among the synced apps as displayed via iTunes.
Fix 4: Delete and re-install the apps
It is possible that you can still delete these apps via the Settings menu on your iPhone.
Open Settings -> General -> Usage, then wait for the list of installed apps to appear.
Once the list populates, find your app, tap on it and then choose ‘Delete App’. Once the app is deleted you can fresh reinstall it.