Theoretically this article should not exist, but sometimes Apple services work beyond anyone's imagination.
If you ever received iTunes Connect's status changed mail. You may notice there's a note from Apple.
It can take up to 24 hours before your app is available on the App Store. This delay is dependent on any app availability issues.
24 hours? kidding?
The sad things is, if your app not appearing in App Store by 2 hours, it won't appear by 24 hours either.
@saiday hey man, did you solve this issue? mine is there for 3 days now!
— Leonardo Maranhão (@lmaranhao) April 19, 2016
Tricks
Go to iTunes Connect, remove your app from sale, undo it.
You app will appear in App Store immediately.
Good Job! Apple!