“Kids don’t feed, clothe, and shelter themselves you know, so we’ve decided to hold an “App Cubby Jr” sale. This week only, you can buy any App Cubby app for twice the normal price! 100% of proceeds go toward diapers, food, our insurance deductible, and other baby related expenses.”

I already own all of David’s apps, and depend on Trip Cubby. I met him last February at Macworld Expo. He’s a good guy who makes super apps. Support him.

While using Gas Cubby, I realized how an application’s features and benefits affect its longevity. Specifically, the features attract your attention, while the benefits grab you for good.

As I said at TUAW, Gas Cubby makes it easy and even fun for me to record my automotive expenses. And that’s crucial, because if something’s fun to do, I’ll be more likely to repeat it. The best part of this app is the charts. Perhaps is my years of training in ABA, but I love analyzing data via charts.

Those are the features.

The benefit is peace of mind, and that’s why Gas Cubby is a keeper. It’s important that I record this data, and other methods were failing me. I’d be stressed that I forgot to write down some service, fill-up for other travel expense. That would bother me and potentialy make tax time a hassle. Gas Cubby eliminated that worry.

No, it doesn’t fart, illuminate a dark room or use the iPhone’s unique features (like the accelerometer) in a “because we can” manner. Those are features. That’s the real reason I love this app is the benefit: It allows me to know that I’m doing what needs to be done, and that’s worth a lot more than $9.99 to me.

For more on Gas Cubby, check out my supplemental post.