jBidwatcher for Mac lets you search and bid on eBay auctions through an easy-to-learn interface. It can place bets on your behalf, seconds before an auction ends, a practice known as sniping. Other features include drag-and-drop integration for adding auctions right from a browser, the creation of custom tabs, customizable double-click actions, My eBay integration, and advanced features like setting up a remote database, proxy, or firewall exclusion.
jBidwatcher for Mac requires Java. After installing the app we encountered a peculiar error where the OS thinks the app is damaged and recommends deleting it -- we resolved this by allowing the system to run apps from unidentified developers. The interface is uninspired but usable and includes several preloaded tabs and the ability to create custom ones. Auctions can be either searched for or added via the auction number or by dragging and dropping URLs. When placing a bet or sniping, you're given the option to set the shipping cost and decide whether to include it in the final bid amount. If sniping, you can also set how many seconds before the end of the auction should your bids be placed. During testing, we discovered that there can be a few seconds of lag depending on network conditions; the optimal time is around seven seconds.
If you're an avid online shopper, you will appreciate jBidwatcher for Mac. It's a useful, little tool that can really save you money. But since it requires your eBay credentials, make sure you use a unique eBay password that you don't use for any other online account, especially for PayPal, else you may run into security issues.