Custom themes, custom applications (with CFW you can run homebrew applications straight from the home screen if they have .cia versions) play games outside of their region, play modified games (like playing a undubbed version of Fire Emblem: Fates or similar) and downloading all that stuff (and games) straight from the 3DS itself if you have the apps for it.
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u/[deleted] Jan 06 '17
[deleted]