Version 0.97 of ical2org is available at
https://github.com/rjhorniii/ical2org-go. It converts from Ical format,
e.g., .ics files, into an org-mode file.
It is feature complete. It has been tested with ICal files from several
sources, and it is successfully processing my personal Google calendar
with a regular repeating automatic download. It's ready for wider use.
After a few weeks use without problems reported, I'll make it a release.
For mu4e users, I've tested using attachment pipe processing with it.
It does correctly convert ics files that are attached to emails, but the
process is awkward. There is a lot of typing. Creating a little lisp
command for mu4e is likely the right solution.