Manual accounts are updated by you and not connected to any bank. This way, you can track anything... from valuables like jewelry, real estate, an bank account that can not yet sync, or to track cash-on-hand.
To add a manual account, select the account type and add any relevant information as in the picture below.
Now that you have a manual account, you can update the account total by either adjusting the balance or adding individual transactions.
Learn about adding manual transactions here!