How can I verify if an accessory that uses a Lightning connector is a licensed accessory?
Click THIS link
Select Brand and Seach 'Avantree'
Below highlighted in green is this Swan which is MFI Certified Lightning Cable.

Accessory with MFi logos. Made for iPod, Made for iPhone, Made for iPad logos has been designed to connect specifically to iPod, iPhone, or iPad, and has been certified by the developer to meet Apple performance standards.