Its great that you're developing your own app, and have it on the App Store, but I've just got a few issues with it after having quickly glanced over it:
1) Not to bash your app but what separates it from other pedometer apps? I find the App Store is already over saturated with them.
2) Not a massive fan of how you've incorporated ads. The advert blocks too much of the screen covering both the "7 days" text and half of the number. The advert bar also covers your "back to home" button on your information page, forcing me to relaunch the app to return to that page.
3) Interms of the sharing buttons: I would be more inclined to use them if they shared the amount of steps i've completed (either daily or weekly) instead of just blindly recommending the app to my friends. I also think you should try using different icons for these buttons as they don't fit in with the general style of your app.
4) I'm not typography expert but as an end user your mixed capitalization in the app seems out of place, as most elements are in lower case with sporadic capitalization. Personally I think it would look nicer if they was more consistent.
5) It would be nice if you could find a way to show me the distance i've traveled in km or miles on the front page, maybe with me tapping to change between steps and distance.
But it really is great seeing people try their hand at developing apps
