Glimmer - Fast and light-weight UI components for the web
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Preact.js - Preact is a fast 3kB alternative to React with the same modern API. Components & Virtual DOM.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Svelte - Cybernetically enhanced web apps
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.