You don't need to use the official Mastodon apps, they're not the best way to use Mastodon. The official apps only arrived last year, and they were intended as "Fisher Price My First Mastodon" things with a restricted set of features.
Third party apps have been around longer than official ones, and include way more features. You can sign in with the same account on all apps.
On Android try Tusky, Fedilab, Megalodon, Tooot
On iPhone/iPad, try Toot!, Ice Cubes, Ivory, Mona
@feditips If I may, what are the key differences between the android apps? Which one would you recommend for somebody who's used to Twitter?
Tusky is a really well-established solid app that does Mastodon really well and has lots of options to customise.
Fedilab is a more general app designed to be used with many kinds of Fediverse server, not just Mastodon.
Megalodon is an unofficial version of the official Mastodon app with missing features added.
Tooot is a newer Mastodon app.
All of them are free open source software.
If you had to pick one, try Tusky.
@feditips excellent thanks matey