Android Application Development

Write here (for an easy grade), what feature / library you thought was the most promising for your final project.  What did you like about it?

Choose from either 2020 or 2017:

https://medium.com/better-programming/25-best-android-libraries-projects-of-2020-summer-edition-dfb030a7fb0a 

https://www.freecodecamp.org/news/25-new-android-libraries-which-you-definitely-want-to-try-at-the-beginning-of-2017-45878d5408c0/