Separated home apps or forums

Google calendar works well. You can set up a family calendar, or just invite each other to events (DC to X's house 5pm, parents evening, etc) You can also put details in there and get notifications when anyone adds something. Google docs might be useful if there's longer things you need to share but personally I've never found a need. Emails or texts work well. Google is free

For sharing photos we use Lifecake

My suggestions: Google or Slack. Slack is free up to 10,000 messages. Photos can be shared (upload and download easily) and there is calendar integration (though I have not used that feature). You can also make notes and reminders for yourself.

Google has features you can share like calendar, documents. Create a team and invite whoever into the team to view and edit documents. I tend to use Slack though so can't really add much more on Google.

Hope that helps.

Seriously, I found just texting mine to be the best way forwards. We’ve been through loads: school exams, changes, new partner rules, attitudes in kids. Great balance and always available....