Then why don't you ask in
their forums how
they make their apps portable? The very fact that Sigil Portable only comes from their website, is a clue that they are the ones who have a clue how to do it.
...
Yes I know they are lagging. That is what happens with less-popular apps when most users don't contribute anything whatsoever to maintaining the apps.
You can tell I know -- take a look at the "fixes bug xxxxx" on their Outdated Apps page.
