Nintendo rolled out a new 3DS system update today, adding one feature that'll be hugely appreciated by the few who need it, and one tweak that's just kind of useful for everyone. One's downloading from the eShop with your 3DS in sleep mode and the other's transferring saves from physical games to digital editions of them, but which is which!
People who bought games on cards then, for some reason, decided to ditch them and buy a digital version were previously unable to continue saved games. Thanks to the new Save Data Transfer Tool, they'll be able to carry the data across. However, it can't then transfer saves back to work with a physical version again, if you're awfully odd and want to try that.
As for background downloads, Nintendo explains that you can now download things in sleep mode even if the eShop app is open. "You can simply close the system cover to activate the Download Later feature and the item will begin to download."
If you don't know how to update your 3DS, here, follow Nintendo's instructions.
Supposedly some have been trouble with the Japanese version of the update, but should that strike internationally, you can simply follow the instructions spotted by Tiny Cartridge.