You can get Obsidian Mobile for iOS and Android via the obsidian website or by searching their respective stores. Since Obsidian is so new as a mobile app though, it's ranked pretty low right now on both. The developers would really appreciate it if you could review the app in the stores so people can find it more easily.
News about Obsidian Mobile is also on Product Hunt and Hacker News today. I was asleep when the launch happened and have really been enjoying reading the comments (and answering questions, lol). If you're a member of either community and want to swing by the threads to share your experiences or help out with questions, we'd all appreciate it.
It was released under the same licenses as the desktop version, which means that if you want early access to insider builds, you can still upgrade to Catalyst for the latest-and-greatest mobile version news and testing.
PS: Thanks for filling out the survey! I've never done a survey before so there were some bumps and kinks I'm still working out (segmented newsletters are harder than I thought they'd be!), but I really appreciate how nice everyone has been about this as I learn :) I just wanted to try and give people who aren't active in the Discord or active on social media would have a way to find out about the Mobile launch, since unlike most updates, you won't see it from a button within Obsidian.