DataAnalysis
Developer: Data Evaluation Systems
Free
Available for iPad only

Thanks to John Forte for suggesting this app

This app plots and analyses any data that can be formulated as x, y pairs. Data points are entered directly into the editor as x, y values, one pair per line. After entering your data, you can average the y value for all x, y pairs that share the same x value, perform a baseline correction to subtract lowest y value, and normalize the y values.

Once all your data is in, the points are plotted on an x-y graph and you can enter independent values to perform non-linear regression analysis. The chart can be customized by choosing a data point symbol and its size, point connector line size and color, labels for both x and y axes, and a title for the chart. You can also choose to connect points, and force x or y axis to zero.

The program defaults to a linear fit (y=mx+b), but there are 16 total functions to choose from. Tapping on the “Fit” button connects the points on the graph with the selected function. The data and the graph can be exported via email as a PFD or a png file, saved as a photo on the iPad, copied for insertion in another app, or saved to a Dropbox account. Data can be imported into the app by cutting and pasting, via email, or by using Dropbox.

I found this app to be very intuitive and easy to use, a great tool to analyze all sorts of experimental data. All graphs you create are saved within the app for later access, and it comes with a few data files to get you started seeing how it works. I found the help feature very useful and easy to follow.

App-A-Day Site:  http://www.smchigh.org/ipadapps/dataanalysis/
iTunes: https://itunes.apple.com/us/app/dataanalysis/id375603883?mt=8
Developer: http://www.scidataanalysis.com/sda/main.html