Pros: Uses iPhone GPS to determine proximity to speed traps, speed cameras, and red light cameras; audible warnings even when iPhone locks itself; users can easily report speed traps.
Cons:Red light and speed trap warnings can sound off too frequently.
The gist: Short of using a radar detector, Trapster identifies hazards to your driving record through an active community. This type of information used to travel by word-of-mouth, but Trapster makes it readily accessible.
2. Cheap Gas
Pros: Lists fuel prices at specific gas stations around your current location; tapping each entry displays prices for regular, unleaded, premium unleaded, and diesel.
Cons: Button to map each gas station doesn't work properly; fuel prices may not be up-to-date.
The gist: Being able to find the cheapest gas within your proximity at a glance will save you quite a bit of money over time. Cheap Gas is especially useful in unfamiliar areas.
Pros: One-button interface for marking car location; interfaces with Google map app for directions, can be used to mark locations other than parked cars.
Cons: Can only mark one location at a time.
The gist: There are many apps for finding parked cars, but Take Me To My Car is free. And how many features do you really want in a simple car finder?
Pros: Includes useful tips with repair estimates; local repair shop search specific to car makes; one-touch access to roadside assistance.
Cons: Model years before 1990 not represented.
The gist: RepairPal is useful when you've got a breakdown, giving good advance knowledge of what to expect from the repair bill.
Pros: Two modes to start a timed run; shows 10 mph increments leading up to 0 to 60 mph time; calculates horsepower.
Cons: Free version filled with nag screens; need a stable mounting bracket for accurate statistics.
The gist: PocketDyno is the cheapest performance computer you can get, as long as you already have an iPhone or iPod Touch.