Each cash account that you set up will fill with transactions. Use the cash browser to examine these transactions.
To show the cash browser, go to 'Estate...Cash balances'.
The list of all cash accounts is displayed in the left pane of the cash browser, the postings for the selected account(s) are shown to the right. If you right-click on the list of cash accounts you can even choose ‘select all’ to display all transactions from all cash accounts. The reconciled status is shown by the check box column in the list of postings. Click on the header of the check box column to sort postings by their reconciled status.
You can simply toggle a posting's reconciled status by using the Ctrl+R hotkey combination. Alternatively you can right click on a posting and select 'Mark/clear this posting as reconciled'.