I have it and it's interesting, but I don't use it much... It bothers me how you can't delete frames. You can erase the whole canvas if you mess up, but you can't delete the frame itself... idunno. it's good for people who like to animate (obviously)
i got it back when it was a free gift you got when you signed up for my nintendo.
tbh i'd never heard of flipnote studio on the dsi until after the internet stuff on ds was shut down, so i have no idea what the online stuff on it was like.
but i only really use fs3d to make notes on stuff because i'm terrible at just drawing a non-animated picture, never mind an animation D:
I've made a couple little Flipnotes, and it's surprisingly well made. Its not like you can make masterpieces on it, but its pretty nifty. Also, its extremely nostalgic because I used to make them on my friend's DSi YEARS ago. Here's one I made ^-^ https://www.youtube.com/watch?v=RlwCn_RGxqk