Use Amazon Smile to give back to charity when you shop. You can choose an organization dear (or local) to you and shop as normal. However, it's important to note that only about 0.5% of every purchase makes its way to charity, and you might do more good by giving more tangibly elsewhere. However, if you don't let shopping through Amazon Smile negate all the good you would have done otherwise, it's a great way to maximize your shopping.
I do not like the security of this apps. By default any one in my home can just open it up and start buying things on my account. I would like it to just add things to my cart on the TV and them buy on "My" Computer or "My" phone. I know you can setup a PIN for "videos, purchasing and certain types of content".But, you then need to enter the PIN for $0 videos. Also, anybody with access to the Fire TV remote can just install the apps and start buying things, no pin, no password, just because you have a Fire TV setup on your account. Amazon you need to have a separate PIN for Buying videos, parental control (ratings), Apps and Shopping. And by default the app should setup a PIN.