Customizable Page Header Obsidian Plugin
This plugin lets you add buttons that execute commands to page header in the mobile (and desktop, off by default) app.
It lets you choose from all commands and configure their icons. You can set icons from the core and feather icons.
Shoutout to @phibr0 for his awesome work on the Customizable Sidebar Plugin. The code that powers this plugins' settings (adding/removing commands/changing icons) is powered by an adapted version of his code.