Even more so than the DSi I was using to take pictures, I nursed my 3DS during a lot of the trip. I played it on the plane, I played it on the bus back from London (showing Caby all the glitches in Pokémon Blue while I was at it >w>), I toyed with some hacked software, since I have it homebrewed—got Doom GBA on there, because that rocks, and I have the built-in DSi apps like the camera and the web browser wrapped as CIAs for shits and giggles. I'm also very pleased to have the "White Knuckles" video on my 3DS now, as an OK Go fan who didn't own a 3DS back when it came preinstalled on them.
Caby also has a 3DS XL, the same one I do, actually (this is another reason we're getting married), and I was eager to hack it and get her going on hShop while I was over. Unfortunately, Nintendo complicated the process with a post-eShop closure firmware update that killed a lot of the former no-game homebrew entrypoints, and while she wasn't running that firmware, Seedminer still failed, so I'd need a flashcart or a game to homebrew it. The one I ordered to show up at her house never actually made it to the UK (in fact, I don't think I was even charged for it), so no 3DS hacking actually occurred. Sad.
I was able to hack her DSi XL, though—and that wound up being a lot more fun in the end. She's been wanting that thing homebrewed for a while now for a single reason: it didn't come with Flipnote Studio, which is a legendary little app for adults around our age and one Caby was so obsessed with, even her parents remember it.
Flipnote Studio is a creativity toy for the DSi where you make these short little animations called Flipnotes, with the ability to upload them to an online hub called Hatena. Hatena also allowed you to watch other people's Flipnotes, comment on them, and download them as a base to make new Flipnotes with. Hatena's since been cloned into Sudomemo, which is going strong to this day and is easy to get patched into Flipnote Studio.
Back to Caby's quandary, while the XL has a much larger screen (obviously better for drawing), hers didn't come with it preinstalled, and mon's efforts to get it on there a few years ago by instructing her to reset the DSi back to factory defaults didn't do anything (which, I mean, why would they). With a hacked DSi, it'd take no time at all to get Flipnote on there for her, and knowing how much she loves it, I did exactly that.
Homebrewing the DSi
The process of homebrewing a DSi can involve a couple of different exploits, the easiest one being Memory Pit. Memory Pit uses a specially-crafted DSi Camera library file to get the DSi to boot unsigned code, either a homebrew application or the installer for a more involved firmware replacement (which is what I did). You run the DSi Camera tutorial if you haven't to get it to create a library file on your SD card, switch it out on your computer for the crafted one, try to view your photos, and you get thrown into TwiLight Menu++, where you can install the custom firmware Unlaunch and run whatever you want, games from other regions, developer tools, the works.
I've already done this before on the DSi I was using to take pictures this trip, so I was familiar with the process (if not totally keen on all the details). Thankfully, the Nintendo homebrew and hacks guides are literally step by step these days, and all the apps and exploits are highly mature and stable. Basically, you have to be trying to destroy your console by not following the steps.
Sure enough, within a half hour, Unlaunch was installed, I configured everything to be completely transparent (I could even set the DSi to boot into Flipnote directly if I really wanted to), we got Flipnote Studio going, Caby set up a new Sudomemo account and patched the DNS on the XL to use it, and we were ready to rock and/or roll.
Caby's Flipnotes!
For basically the entire week after, all Caby did was draw Flipnotes. I loved it! They're quick to make, they're silly, they're a lot of fun to watch, she's terrific at animation, and she had a lot of fun ideas involving her characters and all our sonas. We'd be out somewhere, and she'd be all itchy and tell you she was thinking of going home and drawing Flipnotes. Absolutely adorable, gosh... One of our favorite memories from the entire trip was me napping next to her in her bed, into her shoulder, as she drew Flipnotes, sleepily peeking at the progress she'd made when I woke back up. I could be like that forever, honestly.
Below are the ones she made on the trip (not counting memes or slideshows); click the thumbnail to watch them on the Sudomemo site, audio and all. You'll be totally shocked to hear that people loved them~... Apparently to the point where someone ripped the Wolf Caby Flipnote and reuploaded it to YouTube on their dedicated Flipnote reupload accounts. (This same account reuploaded the Colton/Pennyverse Flipnote she made back in 2019, which I still can't watch. What a sad and strange time for my characters.)