What’s it supposed to do?

I loaded this ap hoping that it would notify me and/or allow me to quickly access gmail because I can’t figure out how to get a GMail icon on my iMac desktop.
It worked once but then stopped worked; the error message says that it is not possible to open the application.
Maybe I’m missing something because it seems to be working for some people but I can’t recommend it. Plan to delete it today.

Fit410S about App for Gmail - Email Menu Tab