That would have been my quick approach. The logo still stands for an "F" like FileMaker, but could also symbolize lines of code, a list view or apps in the OS. Personally, I like a reduced approach more.
This took me about 30-40 minutes to do now. With more time you could surely come up with something better.
However, I have to admit that I didn't check if there are similar logos already that could lead to copyright infringement.
and easily add something that looked pretty darn close to their logo to meeting invites, emails, tasks, etc. Was very scannable.