Is there a use care for Godot for cross platform app development instead of something like Electron?
Yes, although the first-generation of apps are only just beginning to emerge. Here are a couple of fully-featured projects on Github:
Pixel art editor: https://github.com/Orama-Interactive/Pixelorama
Infinite canvas drawing tool: https://github.com/mbrlabs/Lorien
Trello-style kanban board: https://github.com/alfredbaudisch/Godello
Narrative designer for games: https://github.com/mhgolkar/Arrow