Hiya,
Nice little app! If I was being picky I'd say it's an odd mix of fonts across the interface, but otherwise looks pretty nice
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
However… this is an app you're asking people to entrust their MtGox login details to. What assurances can you give us about security? I assume MtGox make you use a secure connection to the server, so I hope that isn't an issue, but what about the app itself? Does it store the login credentials you give it - if so, does it use its own store or use the Keychain? As this appears to be a closed-source application, how can I be sure that this application isn't secretly a trojan capturing account details?
Understand that I'm not trying to criticise you, but that you will need to have (good) answers to security questions. I wouldn't trust a third-party website with my MtGox credentials, so why would I trust an application with them?