My order says OurFamilyWizard (or similar)

Use the named app

Messages, exchanges, or expenses the order says must go through that app should go through that app. Ask your lawyer if a line is unclear. Do not guess.

What you can still do on your own

You can keep a private, facts-only record of what you observed. You can track kid costs you paid even if the other parent will not join a second tool. You can write a parenting-time calendar for yourself so you stop missing days.

None of that replaces the named app. It is your own file.

Do not move the official channel

Do not tell the other parent to abandon the named app. Do not treat a new login as the court-approved record. If you want to switch later, that is a modification conversation with counsel, not a weekend project.

Questions

Can I still use a free calendar for myself?

Yes, as your own reminder. It is not the official record if the order named a different channel.

What if the other parent refuses the named app?

You still use it for what the order covers. Document the refusal in facts. Ask counsel before you invent a substitute channel.

Is Harbor a replacement for OurFamilyWizard?

No, not if an order names another app. Harbor can still be a private journal or a solo calendar. It does not override a court-named channel.