from Hacker News

I'm about to release an app that will require users to give up some info, such as email. The data can in some cases be used in the backend for other services. It's not being sold; we will use it to extract meaningful data to create extra services.

I'm looking for boilerplates/something to build upon which lets me use the data, and in some ways integrate the user data with third-party services.

Do you have any suggestions on open source or free to use resources? Going to a lawyer and having something written up is too early at this stage.