CalCollapse
Collapse your Google Calendars, webcal feeds, and .ics files into one iCloud calendar you already have, so everything you have committed to shows up in Apple Calendar in one place — on your Mac, your iPhone and your Watch.
What it does
Reads the calendars you pick
Google, a webcal feed, or an .ics file. Only the sources you pair are read.
Writes them into a calendar you already own
You choose an existing iCloud calendar. CalCollapse never creates, renames or deletes one.
Keeps them current, within the minute
Changes usually reach iCloud within a minute of you making them, and every 15 minutes regardless. You can trigger a run yourself at any time.
Goes one way, on purpose
Events flow into iCloud and never back. Google access is read-only.
Nobody gets emailed
Copied events carry no invitations, so iCloud cannot mail the people on them.
Busy blocks on the paid plan
A switch on each pair can hide titles and details, leaving only busy time.
Getting set up
You sign in with Apple, connect iCloud with an app-specific password, then connect a Google account, paste a webcal URL, or upload an .ics file, and pair a calendar with a calendar. The walkthrough shows every screen before you hand over anything. Looking for a particular job — Google onto an iPhone, a webcal, an .ics file, or a comparison? See the use cases.