SITI is a simple time tracking tool that fulfils all your needs for tracking a projects time. Without ads, unwanted features or distractions it focuses on the core features, the bare minimum of what you need to accomplish this task.
You can create multiple projects, start and stop a session for specific projects, edit the sessions afterwards, give them a description of what has been done or add a not yet recorded session afterwards. Thats it. And for everyone needing a structured project overview you can export it as a CSV file importable by every spreadsheet software imaginable or as a PDF file.