There are much more features in SaifishOS blocker called phonehook (e.g. checking with online sources):
https://github.com/omnight/phonehook
https://github.com/omnight/phonehook-sources
or
https://sourceforge.net/p/scumstopper/code/ci/master/tree/
It have compatible license and it is written in c++/qml
There are much more features in SaifishOS blocker called phonehook (e.g. checking with online sources):
https://github.com/omnight/phonehook
https://github.com/omnight/phonehook-sources
or
https://sourceforge.net/p/scumstopper/code/ci/master/tree/
It have compatible license and it is written in c++/qml