iPhone 4 contacts disappeared after power cycle

This morning I reinstalled the NPR app which didn't work after latest update. App store recommended the deletion/reinstall.

Was using Pandora, went to send a message - kicked out of message 3 times in a row. Did a power cycle on and off.

Went to send message and noticed all names converted to phone numbers. Nothing in contact list.

I don't sync to computer or iCloud (yah, yah, I know)....but this is odd. How do I fix it? Powering on and off one more time did nothing. I'm afraid to do more. Left swipe search does not show any contacts.

Advice? On reading other threads, it's happening to lots of folks but no real fixes there. Help!