All-in-One Regression combines linear regression, multiple linear regression, curvilinear regression and multiple curvilinear regression into a single easy to use package. This app is more sophisticated than previous due to a number of new features. For example, it will allow the user to change regression types within the same project, so a linear relationship can be tested as a curvilinear relationship without switching projects. Data can be edited or deleted within-cells making this tedious chore much more efficient. Data can also be entered in batch mode from a text file, in addition to manual data entry. Both 2D and 3D graphics are available for all regression types. Reports can be output as text files for insertion into research manuscripts. All data is stored in a database for efficiency and future reference.