The UI for “adding a note” is basically just replacing the title. When you replace a title the original title change will be the main text listed in the transaction and the original title will become a subtext so you can will always know what the original charge was labeled.
To change the title of a transaction you simply tap it. The editing interface for changing the transaction’s name will appear.
The transaction and the original title will become a subtext (as in this screenshot – original title was Amazon and note is “Ear plugs”).
When dealing with a split transaction, the text under the Split (Split 1 in screen below) will be the title.
Changing the title of a transaction helps you label transaction in a way that can help you understand what it is for while keeping in tact the original transaction title delivered from the bank. This effectively helps you add a note or label to your transaction so you can remember what it was for.