First of all, I respect your gesture here and can only hope for the best for you... Now for building an app that uses Shazam's database and detection algorithms, the only thing you can do (since it's not open source) is to reverse engineer the app most probably the one from Android)... That's what the wazapp team initially did.. That's really the hardest part in the development really.. After that it really shouldn't be hard to build the app with Qt.