Android 4.4 KitKat contains contains APIs which handle the more "difficult"/low level programming of a step counter for you (assuming the phone in question has that hardware). From what I have read about the Optimus 34C, it doesn't seem to come with that step counter hardware so you will indeed need to code it yourself.

I am currently working on an app for Android Wear in which I am using the accelerometer of the watch to trigger a method. Since I found that programming this accelerometer code wasn't too difficult and, in my experience, my watch's pedometer is rather accurate, I think you will probably be able to code a decent pedometer for your app on your own.