I can't find voice memo app on my iPhone 7.

Hi

As you cannot locate the Voice Memos app even when searching on your iPhone, you may have previously removed the app.

If so, to add it back, tap on this link on your iPhone:

Voice Memos by Apple: https://appsto.re/gb/gx3V_.i

Perhaps you deleted it.

Open the App Store on your iPhone. Under the "Featured" tab, scroll way down to "Apps Made by Apple". Find the app there and download it.

That's interesting.

Might it be one of those 17 apps in the "Updates" area?