Can I share project files with my friends?

Using the dedicated Chordcat Manager software, you can save projects you've created on Chordcat to your PC/Mac. You can then share the ".prj" files you saved on your computer. Use Chordcat Manager when you load ".prj" files on Chordcat.

For details, see the "3.2. Project window" in the Chordcat Manager user manual.
You can view the Chordcat Manager user manual in Chordcat Manager.