PowerCMS comes with the Admin Panel, but it's not a part of a main project repository, to let anyone choose if he wants to use this one or write his own. Panel is written in React, using PowerCMS react-kit package. It's very clean, simple, and mobile ready.
How to use?
Clone the repository first
git clone firstname.lastname@example.org:power-cms/admin-panel.git
Feel free to fork it, extend and use for your cases.