clipgrab as alternative to youtube-dl

[Fred]

Hello,

I would like to try clipgrab as youtube-dl sometimes doesn't work.  I 
would not have made a donation on the clipgrab web site if I had first 
noticed that no support what so ever is available.

There is a binary for Linux available for download as a AppImage file. 
What is an AppImage file and what does one do with it.  The program was 
probably compiled for Ubuntu.  Is it likely to also run on Debian?

I also looked into compiling the source code which is often as easy as 
following some simple instructions.  The compile makes use of qmake 
which gives the error:

qmake: could not exec '/usr/lib/i386-linux-gnu/qt4/bin/qmake': No such 
file or directory

/usr/bin/qmake is a link that points to /usr/bin/qtchooser which is 
picking the wrong version of qt.  Qt5 is needed and is installed.  I 
have set an environment variable QT_SELECT=qt5 but the chooser is not 
fooled.  So, if the binary is not usable how do I select qt5?

Best regards,
Fred