the app sounds good. I also lost (ok, it was only 20 lbs) by eating better and exercising more.
For a while, I just kept a text list of what I ate (incl. cal. count if it was easy to find), and then if I wanted to know how many cals I went back and did addition or guessed.
Just the act of writing down what you eat is an eye opener for most people. it also lets you observe nutrition, variety, time of day and other non-numeric things.

As a guy in my .mil unit once said, "you can't outrun a bad diet"

-John

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2009 Kia Sedona
2009 Honda Odyssey EX-L
12006 Jetta Pumpe Duse
(insert Mercedes here)

Husband, Father, sometimes friend =)