I've been enjoying Firefish for my Mastodon content. I like the extra features and interface better than stock Mastodon.
Though, unless I just can't find it, there doesn't appear to be any way to follow a hashtag on Firefish, which is a bit of a bummer. The antenna feature is alright at filling in this gap, but it's not perfect.
Firefish works mostly okay with third-party apps, but none of them seem to be able to do some of the more advanced features like the live, auto-refreshing feeds, which is a feature I rather enjoy. So I've been pretty content with just using the PWA on my phone for the time being. The mobile interface is solid enough that I don't feel a strong need for a dedicated app just quite yet. Notifications can be delayed by a few minutes, but I can tolerate that.