DEVMENU is a Nintendo Developer tool used to install CIA packages onto the 3DS. Due to the nature of the file, we cannot distribute links here, but many people recommend it.
Also, you can use Themely for themes, but people have recently been recommending the new 3DS theme manager Anemone3DS by @astronautlevel. Use either Themely or Anemone3DS while you wait for the update.
You would think that FBI would have fixed that issue by now. Has it?