These aren't specifically about Qt or GTK applications (except maybe the Ubuntu phone app), but here are some other projects that are shooting for compatibility

These aren't specifically about Qt or GTK applications (except maybe the Ubuntu phone app), but here are some other projects that are shooting for compatibility: https://github.com/f41c0r/textsecure-client https://github.com/f41c0r/textsecure-client https://github.com/AsamK/textsecure-cli https://github.com/AsamK/textsecure-cli https://github.com/TerrorM/pytextsecure https://github.com/TerrorM/pytextsecure https://github.com/janimo/textsecure.git https://github.com/janimo/textsecure.git https://github.com/janimo/textsecure-qml https://github.com/janimo/textsecure-qml https://github.com/StarfishInteractive/Norvos https://github.com/StarfishInteractive/Norvos