Items
The default application created when you start a New Multiplatform App project with Xcode is one the all time greatest pieces of art.
When you first run it, you see this:

Select an item
It invites me to Select an item, but there are no items. What now?
Ay, I'll press that ➕.

An item!
Fantastic! An item! I look forward to selecting it.

There it is
Ay, there it is
My item

I can have as many items as I like.
During setup I selected Core Data and CloudKit, so my items are synced across all my devices and are available wherever I need them.
This is the perfect application. Any time I have an idea, or see an article I'd like to read later, I will create an item representing it in my Application.
Thanks