We will not link directly to ROMs, but below are reputable, long-standing archives known for clean dumps.
If you want to relive the glory days or experience the fabled "Flipnote Frog" memes for the first time, here is how the community does it: Flipnote Studio Dsi Rom
Nintendo officially shut down the DSi Shop in March 2017. This means you cannot legally download Flipnote Studio onto a stock, unmodified DSi. We will not link directly to ROMs, but
However, the software is preserved in digital archives. The Flipnote Studio DSi ROM (usually a .nds file) is widely available, but there is a catch: Nintendo implemented a "console lock" on the software. You cannot simply drag the ROM onto a standard flashcart and play it. The app checks for unique DSi signatures. However, the software is preserved in digital archives
(Provide offsets in a specific dump; here only conceptual mapping.)