I’ve made an app that makes it possible to schedule a post in Lemmy at an arbitrary time. It’s available at https://schedule.lemmings.world and can be used by people from any instance.
Let me know what you think!
P.S. This post is made using the app!
Edit: And it’s open source!
With a mobile client, for example, you can check if it sends your password somewhere else, there are tools. If you use an open-source client then it’s even easier. Major clients have something that you could call reputation, though I wouldn’t put too much trust into it.
Here I know for a fact that my password goes to a third-party: