I implore anyone who can think of a better way to phrase the title, please suggest it.

Essentially, I use a self-hosted MediaWiki which is where I write everything, but when I just have an 'idea', I have a private Discord channel that I submit the information to. It can be a picture, or a character idea, or an idea for a scene or a shop or whatever-- I just have a channel where I dump all of my ideas, and then when I have time, I go back through them, iterate, add them to my wiki (making them 'canon'), and then deleting the messages.

I would really like something else to do this, because Discord is obviously not meant for this. Unfortunately, the caveat is that it needs to be useable on mobile, because I'd say 80%+ of my ideas like this happen when I'm not at my computer.

My first thought was to set up and self-host a ticketing system-- something like Znuny, but outside of using Zendesk for work, I don't really know that much about them, and it feels like it might be overkill (on top of not working on mobile, I don't think). It has the benefit of being able to immediately have the data organized, so I can double-check to make sure I'm not repeating character names, or ideas, or anything like that.

So, with that in mind, what all are my options?