Update 2019.02.19: As a rooted version is no longer maintainable by me, APKs are no longer being maintained here. If you just need the regular APK, please consider using Qooapp (link to SIF JP on QooApp) or an alternative for obtaining and keeping your SIF installation up to date, as they are simpler to use for installing region-restricted Android applications.

If you think it'd be super helpful to include instructions for doing so, ping @sleepingkyoto on Twitter. (I've never actually used it but it seems like it should be straightforward.)