for many older JSJSJS $apps$, $it$ $is$ $possible$ $to$ $just$ $drop$ $them$ $into$ $an$ $app$ $folder$, $and$ $build$ $an$ $ipk$ $and$ $they$ $will$ $run$.

It is unlikely that they will run well or that their graphics will be well adapted to the pre.

The beginnings of a tutorial for porting older web apps can be found at the PreDev Wiki at pre dev wiki: Porting Older Apps