Calendar Planner & Custom Web Search is a versatile extension designed for Firefox users, combining a calendar and appointment scheduling tool with a custom web search feature. This subscription-based extension allows users to manage their schedules effectively by offering functionalities such as appointment creation, reminders, and the ability to color-code events. Users can easily navigate their day, week, or month while also having access to a search feature that provides quick results for holidays and upcoming events.

In addition to calendar management, the extension integrates a custom web search powered by Yahoo!, enabling users to search for news, weather, images, and videos directly from their browser. The intuitive interface allows for easy appointment scheduling by clicking on the calendar icon, where users can add details, set reminders, and modify or cancel appointments as needed. This tool aims to enhance productivity and streamline access to essential information from the browser.