There are several MySQL GUI clients available for Mac OS, each with its own features and strengths. Here are 15 popular MySQL GUI clients for Mac OS:

1. MySQL Workbench: The official MySQL GUI client with a comprehensive set of tools for database development and administration.
2. Sequel Pro: A lightweight and intuitive MySQL client with a clean interface and powerful features like direct editing of data and easy import/export options.
3. Navicat for MySQL: A feature-rich GUI client that supports not only MySQL but also other databases like MariaDB, SQLite, PostgreSQL, and Oracle.
4. TablePlus: A modern and user-friendly GUI client that supports multiple databases, including MySQL, PostgreSQL, SQLite, and more.
5. DBeaver: A universal database tool that supports various databases, including MySQL. It offers a rich set of features for data manipulation and administration.
6. HeidiSQL: A lightweight and easy-to-use MySQL GUI client that provides a simple and intuitive interface for managing databases.
7. SQLPro for MySQL: A popular MySQL client for Mac with a clean and customizable interface, syntax highlighting, and query building capabilities.
8. Valentina Studio: A powerful database management tool that supports MySQL, PostgreSQL, SQLite, and more. It offers features like diagramming, SQL editing, and data modeling.
9. RazorSQL: A multi-database query tool that supports MySQL and other databases. It provides an intuitive interface and features like query building, data editing, and import/export.
10. SQuirreL SQL: An open-source Java-based SQL client that supports multiple databases, including MySQL. It offers a plugin architecture for extending functionality.
11. SQLyog: A popular MySQL GUI client for Windows that also has a Mac version. It provides a comprehensive set of tools for database management and development.
12. dbForge Studio for MySQL: A powerful IDE for MySQL development that offers advanced features like code completion, query profiling, and data comparison.
13. Aqua Data Studio: A universal database management tool that supports multiple databases, including MySQL. It offers advanced query and visualization capabilities.
14. dbVisualizer: A cross-platform database tool that supports various databases, including MySQL. It provides an intuitive interface and features for database exploration and management.
15. Toad Edge: A MySQL IDE for Mac OS that offers tools for database development, administration, and performance optimization.

These MySQL GUI clients provide different features and interfaces, so you can choose the one that best suits your needs and preferences.