Bonobo Labs has Zilla: Digital Dashboard & HUD (iTunes Link) for the iPhone and iPod Touch in the iTunes App Store for FREE (regularly $2.99) for a limited time.

Put yourself behind the wheel of a supercar every day with Zilla, the in-car computer your ride should have come with! Graph your G’s as you accelerate, corner and brake. See your speed, tire loading and other performance stats change in realtime as you drive, with over 14 stunning gauges and readouts. Zilla uses the powerful sensors in your iPhone, all you have to do is put it in your car!

Add Zilla to your ride to entertain friends as you drive, or if you’re into seriously into cars you can use it as a powerful tool to measure your vehicle’s handling and performance.

MapMyFitness has Walk with Map My Walk+ (iTunes Link) for the iPhone and iPod Touch in the iTunes App Store for FREE (regularly $2.99) for a limited time.

Easily track route, pace, calories, distance, time with audio alerts and much more! Friendly, simple to use tracking tools to motivate walkers and help improve activity levels. Weight loss and social tools for those who want them. Play music! This app keeps tracking your run in the background, so you can play your iPod, run Pandora or your favorite music app simultaneously.

Great for tracking any of the following activities: running, cycling, cardio, jogging, walking, weight lifting, dog walking, cross country skiing, unicycling, downhill skiing, snowboarding, gym workouts, weight lifting, basketball, soccer, hockey, yard work, yoga, p90x, crossfit, insanity, interval training, hill runs, rock climing, hiking, mountain biking, road cycling, dance, inline skating, barbell curls, cross training, spinning, roller skating, endurance training, kayaking, horseback riding, rowing machine, elliptical, resistance, commuting, skateboarding, rollerblading, stairs, abs, sprints, golf, lap swimming, open water swimming, triathalon, track & field, group runs, treadmill, stairmaster, weight machines , trail runs, cross country running, and any outdoor activity