Android (with iPhone in the works): Are you the type of person who's always late? Or maybe you always get to your destination too early? Either way, Bounce uses the power of technology (GPS, your calendar appointments and Bing) to get you out the door at the right time.
The app works with Google Calendar and Microsoft Exchange and can remind you up to an hour before you need to leave. The settings let you add some padding to your travel time to allow for things like finding parking.
In my tests, Bounce was a great personal assistant. For nearby appointments (a few blocks away), the app told me to get going about 10 minutes before, with the five-minute padding default I had added in. (Naturally, I would've walked and not driven for the close stuff, but Bounce is really for getting to places you would drive to.)
Bounce adjusted for appointments farther away. As an example, for a place that takes 33 minutes to drive to and has low traffic, the app told me to leave an hour before. Knowing traffic in New York, that's when I would've left too.
There were issues on the first version of the app for users running Ice Cream Sandwich, but the developers appear to have fixed those, and an iPhone version is in the works.
Bounce is currently still in beta, so for very critical appointments, you might not want to rely on it completely (e.g. if you're trying to get to a surprise party and don't want to arrive at the same time as the person being surprised). But for solving the stress of guessing what time to leave without being too early or too late, Bounce is a pretty cool app to help you out.