"More than 40 types of hardware and system diagnostics to help you find invisible smartphone issues. Trade-in appraisal conducted by various channels for used smartphones based on the phone condition to give you a convenient and quick way for trade-in. 1. Appraisal based on the phone condition, provide the most complete information on trade-in prices. 2. Provide more than 40 types of diagnostic tests based on our patented technology to quickly understand the phone status. 3. Provide system moni