Kimai is the #1 open-source time-tracking application. From freelancers to companies and organisations - everyone can manage timesheets, generate reports, create invoices and so much more... Web-based multi-user application, available as On-Premise or SaaS version: https://www.kimai.org
Stop letting your work go unnoticed. Meridian keeps an automatic work journal of what you worked on and what you finished, summarised daily, and automatically drafts your project tickets for you.
Terminal TUI for ClickUp time tracking & billing: monthly hours reports (self + team), per-list rates, billable amounts, and CSV/JSON/Markdown export. Written in Go.
Super Productivity is an advanced todo list app with integrated Timeboxing and time tracking capabilities. It also comes with integrations for Jira, GitLab, GitHub and Open Project.