Honestly, it's one of those things that seems annoying, but I can tell you from experience that the app makes keep tally of what I consume easy. The app allows you to scan the barcode on almost anything prepackaged, so the calories pop-in without any searching. If you're fairly regimented about certain meals, for example I eat the same breakfast nearly every day, you can "copy" previous meals from day to day.
As far as exercise, nearly every type of workout is available in five minute increments - so you can get a fairly accurate read on your calorie burn too.
With less than 10 pounds to go, I plan on continuing to use Lose It! to make sure I don't lose track of my weight again.
(Photo Credit: Lose It)