If you are using BusyBox - make sure you use the right version
We have been using these instructions to generate a filesystem image, which worked a few days ago, but not when we tried again yesterday. The app disappeared after loading the image back to the tablet.
After some searching, we discovered that the problem has to do with the fact that BusyBox has been changed to a new version (v48) as of Jan 14, which causes the original instructions not to work. We managed to download the previous version (v46), and it works fine.
Just wanted to let everyone know if they come across a similar issue.
Thanks all for the instructions. It's been very helpful!