Please scan the QR code corresponding to your mobile phone system for downloading, which is convenient and quick.
IOS9 User Installation Guide
Due to the security mechanism of IOS9, users who install the pen app for the first time need to enter the system "setup"
Select "General" - "Profile" / "Device Management"
Select "An English company name.", set to trust
Click "Trust" to complete verification
IOS User App Store Installation Guide
App Store download requires AppleID country/region to be outside of China Reference link