On ubuntu-16.04-desktop-amd64.iso I get:
$ /home/me/Downloads/mycroft-qtapplication.AppImage 
/home/me/Downloads/mycroft-qtapplication.AppImage: error while loading shared libraries: libpng16.so.16: cannot open shared object file: No such file or directory
 
Please bundle libpng16.so.16 inside the AppImage and please test it on a Ubuntu Live CD.