This is the only single app, which can help you to know all details about which you want to buy, new or old android devices.

TestM- Smartphone Condition Check & Quality Report

TestM- Smartphone Condition Check & Quality Report

TestM- Smartphone Condition Check & Quality Report

My Device Report (TestM- Smartphone Condition Check & Quality Report)

Android (Google Play store)- https://play.google.com/store/apps/details?id=com.testm.app

Official Website- https://testm.com

I tried, now it's yours.