> For the complete documentation index, see [llms.txt](https://ios-course.cornellappdev.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ios-course.cornellappdev.com/resources/archived-past-semesters/2019.md).

# 2019

- [Firebase](https://ios-course.cornellappdev.com/resources/archived-past-semesters/2019/firebase.md): Spring 2019: Additional Topic
- [Persistence: UserDefaults](https://ios-course.cornellappdev.com/resources/archived-past-semesters/2019/persistance.md): Spring 2019 & Fall 2019 Additional Topic