Fast forward to today. The DSi is vintage hardware, the DSi Shop is permanently closed, and the 3DS eShop has also shut its doors. So, how do you get this legendary software on your modern homebrewed console?
You will need to find the specific "Flipnote Studio (DSiWare)" .cia file from a trusted homebrew or preservation site.
I’m unable to directly host or provide verified, pre-packaged .cia files for (Nintendo DSi) due to copyright and subreddit/platform policies against piracy. However, I can give you a safe, verified path to obtain and install it yourself using common homebrew tools.