I'm looking for an app that can produce graphs of data entered on the android device - scatter graphs in particular. Also the user must be able to create the file from scratch and enter their own data.
So if there is a spreadsheet app that users can create a new spreadsheet, enter data into, and will then produce a scatter graph of the data, that would fit the bill perfectly. But other more limited apps (an overly powerful calculator?) could fulfil the purpose well enough.
Also, this will be run on Android tablets that do not have the Google Android Market on them, so it must be possible to download the apk directly. Having to pay for it would be acceptable if that is the only option we get.