I was checking my Github stats and was interested to see a Polish blog linking to Filmulator, so I checked it out.
You can also read it via Google Translate. EDIT: there’s a button on the bottom-right of the native blog that replaces all the text with google-translated results in several languages including English; it’s much more polished-looking than this link.
The gist seems to be that the author likes the results and the simplicity but would like to have a before/after view for changes, and of course more speed. A comment also complains about the fact that it doesn’t have hardcoded paths to the QML files, which is an issue I am looking into literally right now.