Device
- Where can I download application software?
 - Applications in the App Store are not of the latest version.
 - How to download an application when the application market cannot operate properly?
 - The software downloaded from the application market cannot be installed or updated.
 - How to deal with the data transmission fault with a USB cable?
 - Slow charging with the power bank.
 - Sometimes the focus is fast, and sometimes the focus is slow.
 - An incoming call is received, but the other party hears a prompt, indicating that the call is being shut down or being connected.