Flipnote Studio
Flipnote Studio was an application distributed for free with the Nintendo DSi. Flipnote Studio allowed you to create simple hand-drawn animations. You can then add sound to these animations, if you wish. The true entertainment value of Flipnote Studio, however, comes in the accompanying Internet community, Flipnote Hatena. Hatena is where you shared the flipnotes you've made. On Hatena, you could watch other people's flipnotes, download them, and edit them (if the original creator gave you the go-ahead). If people watched your flipnotes and liked them, they may give you "Stars", which simply served as a means of quantifying how much people like them. There are five different types of Stars: gold, green, red, blue, and purple, from most common to least common.
Flipnote Hatena shut down on May 31, 2013, and the application cannot be downloaded anymore, as the Nintendo DSi Shop closed on March 31, 2017.