It’s basically somewhere exactly between the DS and the 3DS. It has games & apps you can get from the eshop (can’t remember if that’s what it was called), it has cameras, but the games will have about the same graphics fidelity as regular NDS games. It had few games exclusive to the DSi. Alternatively just think of it as an NDS with a home menu and eshop
I have my personal inbox set to automatically mark an email as read if it contains the word unsubscribe. It makes managing my email a lot easier