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