There are a lot of travel apps. Some are great, some are good, some are me too. I've taken a look at the just released Flight+, and I'm pretty impressed. This app is loaded with features too numerous to mention. It will track every flight at almost every airport anywhere in the world. The app displays delays, gate information and flight delays in real time. There are also handy seating charts.
Weather is included for your destination, along with a ten day forecast. If you have a Tripit account, it will sync automatically. The alerts are comprehensive. Alerts for departure and arrival time changes, gate and terminal changes, flight status changes, and you can set reminders for departures and arrivals.
The maps are attractive and you can zoom into any flight anywhere. The app has an offline mode so information is available while you are airborne, and you can share flight information via email, SMS, Facebook or Twitter.
There are a few negatives. This is not a universal app, and if you want both you will pay twice. The iPad version is US $4.99 while the iPhone app is $2.99. Features and functions are the same.
Other than that, this is a very useful app. As i said, there are a lot of travel apps with similar features, but I haven't seen one that is quite so comprehensive. If you spend a lot of time in the air and sitting at airports, this app has your name on it.