Some Smartphone apps like Twitter and Facebook are compatible with both iOS and Android platforms. That's because they're so popular, they demand functionality with both. But, there are some apps that are exclusive to one platform and not the other.

Tweetbot (iOS)

This Twitter assistant is super powerful. You'll be able to control multiple timelines, retrieve tweets while operating other apps, mute users without blocking them and much more. This tweet-helper app has much more power than HootSuite, Tweetdeck and others. It's available for $5 on the App Store.

Aviate (Android)

This is another app that gets used to your habits and the time of the day. The app can be customized to deliver traffic and weather reports for when you wake up in the morning. It can also display the apps you use the most on the home screen, and much more. This app is handy and highly customizable, and it's free.

LoungeBuddy (iOS)

Travel much? Hate sitting near the crowded gate with all those strangers? LoungeBuddy gives you the chance to access airport lounges. It will link with your existing frequent flyer accounts and deliver you special offers to access lounges. Sometimes they will be free, sometimes they will be discounted. It will also tell you which lounges allow one-time day passes. In case you haven't been in an airport lounge, it's quite the experience. You'll get comfy chairs, free newspapers, free food and free alcoholic and non-alcoholic drinks. Some lounges even have showers for your use. This is a free app perfect for the airport traveler.

UPDATE: LoungeBuddy is now available for both platforms!

Glove (Android)

If you just moved to a new city, Glove is perfect for you. Glove will run automatically in the background for three days. It will detect the best signals and determine if you should stay with your current wireless carrier or switch to a new one based on signal strength. You want the best signal in your new city, don't you? This is a free app for Android-only phones.