There's only so much I could fit in the title, and I honestly didn't mean to mislead anyone. I can definitely see how it could be a little misleading now that you mentioned it.
Yeah I definitely thought this was sth. about making videos on mobile, but I don't think the title is purposefully trying to mislead anybody. Maybe titles should be allowed to have ~100-120 chars instead of 80, it's a bit too limiting.
Mainly "cross platform". Many people would interpret that as [desktop] platforms, e.g. Linux/Windows/Mac OS. Especially if you weren't previously aware of what Flutter is.
Adding a "mobile" in there somewhere would be a significant improvement.
In addition "movie app" is a bit underspecified. Maybe it's for managing movies? Editing them? Playing them?
Especially when both confusions are combined, it can be easy to get the wrong idea of what the submission is.
Sorry about that!