Hi Jared, I can only speak for the iPhone here but I have found LoseIt to be a very great app for myself. It a nutshell you can track your daily intake of food and see how many calories you are taking in. There are options to view full nutritional details about your food as well, which really helps when your trying to achieve certain daily amounts/percentages (ie protein etc).
Check out http://www.loseit.com for more information.
I used to use LoseIt and I tried the livestrong App. My favorite is MyFitnessPal. Not only does it have the largest database of foods I have ever seen, but it allows you to see how your friends are doing in terms of staying on track. For example when someone loses a pound, it will post it on your friend wall. You can also access it from your computer, where you have many more interactive options. Try it out!
The apps I like for the iphone are SparkPeople, My Fitness Pal, Fooducate, and Nike Training. Those are the ones I am using right now and I really like them.
Fooducate is really cool because you can scan food item bar codes and they get a rating and they also give a healthier option to the item that was scanned!