I don’t know how exactly it will work on Android yet, but on iOS the settings migrate seamlessly and there’s a “legacy” app so you can keep running the old version alongside the new one.
Ack, sorry, I thought this was in reference to our new version 4.0 - the 3.2.95 beta this thread was originally about is already out officially now, just download the latest version of Pleco and you'l already have it.