Those of you who have taken a course or two in statistics have had to solve linear regression and data analysis problems in the past. Apps such as Statistics Pro can help with that. It comes with a collection of solvers with the ability to handle up to 30 inputs. You can use this for data analysis, linear regression, confidence intervals, and random number generation.
This app supports Normal, Binomial, Exponential, and other common distributions. It can perform t-tests for one or two means. You will need iOS 9.0 or later to run this app. More info is available here.