I couldn't find any apps that displayed the data from the iPhone 5s M7 chip's step counter the way I wanted to see the data, so I made my own app. It's called StepChart.
StepChart will display the total number of steps alongside a simple chart for the past 7 days. It is easy to navigate between the days by swiping your finger. Each day has a different color.
At first, I wondered what the best way to fit in axis titles for the chart is. I tried some variations, but everything looked ugly. I came to the conclusion that it is best to keep it simple. It's fairly obvious (I think) what the chart represents on each day. It's meant to give a rough idea of the day's activity, not a detailed analysis.
Here is a sample screenshot:
I'm thinking of adding an eventual weekly summary view that will show the total steps during the week and total steps per each hour in the chart. I will probably make this a "Pro" feature via an IAP.
The app is submitted for review; hopefully it gets approved fairly soon.