In the app there's an option to hide accounts from the balance tab without erasing the transaction history.
- Go to the Balance tab and tap/click "Edit";
- Select the account you want to hide;
- Tap/click the red "Delete" button;
- A new window will appear, offering you to Cancel, Hide and Delete. Tap/click "Hide".
The account will no longer be visible on the list, but the transactions will remain intact. You can unhide the account if you want to (Edit > Select account > Restore).
If you choose “Delete", you account will be deleted together with its transaction history.