Hotels, car rental locations, and gas stations typically reserve a larger amount than the expected cost (say $100 at the gas pump or a $200 incidental hold at a hotel on top of the total cost) because they cannot predict how much available funds are in a debit account. By attempting to authorize more than the anticipated cost, the merchant is assured there will be enough funds in the account to cover the end purchase amount.
With Pocket Protector, the funds required to complete the authorization will be moved over. This means that your Pocket could end up with more funds than required at the time the transaction is posted.
For example, let's say you have $20 in your Gas Pocket and the gas stations you frequent applies a $100 authorization at the pump. Pocket Protector will move $80 to your Gas Pocket to help complete the authorization. Your gas purchase ends up being $45. Now your Gas Pocket will have $55 left since Pocket Protector needed to move $80 to initiate transaction.
You may find more information on card authorizations and holds here.