Pachli is a full-featured client for Mastodon and similar servers.

Read, reply, filter, post, favourite, and boost posts
Translate posts from other languages
Your timeline is cached locally, so you can read when offline
Draft posts now, to finish them later
Write posts now, schedule them to send later
Read and post from multiple accounts
Multiple themes
Focused on ensuring all functionality is available to people with accessibility needs
Open source, https://github.com/pachli