There should be a version in the debian repositories, so it should also be in raspian.
But you can also compile it yourself. For this you need the source which you can get from github https://github.com/fritzing/fritzing-app, then you need the Qt5 development files, as well as those of libgit.
Extract the source code and then run:
qmake
make
make install
It might be possible the some requirements are missing then you have to install the corresponding dev packages for them.