Awesome

StellarQtSDK

Stellar SDK for Qt/C++. Interface to deal with Horizon API

To include the SDK, just add it in your .pro file

include($$PWD/StellarQtSDK/StellarQtSDK.pri)

To see how to work with the SDK, check the two examples included.

There is also a guide to setup the environment and create your first app on the wiki