Recommended Collaboration & User Management plugins for multilingual sites

WP Project Manager is a WordPress project and task management tool facilitating back- and front-end collaboration. Features include comments, messaging, task assignment, file sharing, to-do lists, milestones, calendars, Gantt charts, Kanban boards, time tracking, automatic invoicing, and advanced reporting.

Multicollab streamlines editorial feedback and collaboration within the WordPress platform, reducing the need for external apps. Features include inline comments, team and guest collaboration, tracking, real-time notifications, and suggestion mode.

Atarim is a WordPress visual collaboration tool that streamlines website collaboration through the front- and back-end. It offers various features including role-based access controls, task management, comments tracking, file uploads and automated screenshots, group notifications and inbox, forms creation, and automated reports.  

SureFeedback is a web design and development collaboration tool. It allows real-time feedback, tracks changes, and records feedback for easy reference. Other features include project dashboards, task and user management, compatibility with popular design tools and web development frameworks, customizable branding, and bug reporting/tracking.