My contact app disappeared on my iPhone 8plus how do I get it back?

Hello,

It is likely still there, but hidden somewhere.

Try a search to locate it. Swipe down from the middle of the Home screen to enter the search feature and type Contacts and it should show up.

If not, download it again from the App Store.

Then restore your contacts:

Use iCloud.com to restore and recover iCloud information - Apple Support

Good luck.