[kolAflash]

COOL (Collabora Online) requires some extra infrastructure. See this previous post.

https://news.ycombinator.com/item?id=42251940

I use COOL every day. But I haven't set it up on my low end home server yet, because of the extra resources needed.

[gbraad]

I am aware of the additionals, like COOLWSD. But since they run this in their Android apps, it seems this can already be Pi-ready