I just discovered a neat little app for the iPhone called Weightbot.
I is a weight tracker with BMI and nothing else. But what a beauty! And fun! You can set a goal and it gives you average loss, nice charts and it is just fun logging in results :-)
It is $1.99 but maybe as a reward for reaching a goal or as motivation (in my case!)?
I use My Fitness Pal, to track my food intake and exercise. It has a ton of food choices and you can add foods or exercises if they're not in their database. It's really helping me stay on track.
I also like Target Weight. You enter your goal and it displays a red number on the app icon indicating the number of pounds you still want to use. So it's always reminding me to be good. :-)
Both apps are free and they've definitely helped me stay accountable.
I too use My Fitness Pal for Calorie Counting and weight tracking and also use Target Weight for tracking as well. Both as awesome apps, especially my fitness pal and both are free!