iPaler is a small and easy to use application to store, track and manage your received PayPal transactions and customers. You can create different accounts, products and customers/transactions to these products. If need you can export (.pdf) or print receipts. There is also a portable/network version available. This portable version can even run in your network.
Version 1.1 is Mac OS X 10.5 Leopard compatible.
Mac OS X 10.4 or later