@Gullwing
I had no issues. Can you tether using your PC? If that doesn't even work, there may be an issue with the settings you're using or the app itself. I'm not sure if this app supports your model of phone. The 3DS doesn't even see the connection at all? By default, when scanning for a hotspot on 3DS, the connection should show up as "AndroidTether".
Also, make sure you're using the specific version of the wifi tether app i posted. The ones on the market don't support infrastructure on some phones, only ad hoc. Ad hoc will of course not work on the 3DS.
EDIT- ok it recognizes it but won't connect. Hm... It sounds like the issue i WAS having with other versions of the software. Your phone may not be supported for infrastructure mode yet, only ad hoc. In your pc, go look at the wifi connections and look at the tethering icons. If you see the android tether connection with some green bars, that's infrastructure. If it's just an icon with some blue computer monitors, it's ad hoc. You NEED infrastructure for the 3DS to tether. Test it on your PC to see if you can connect properly using infrastructure.