Price Tracker от exzzy

Price Tracker watches product prices in the background and sends you a
Firefox notification the moment a price changes.

Features:
• One-click tracking — open the popup on any product page, the price is
detected automatically, click "Track price"
• Works on Amazon, WooCommerce stores, and any site using standard
product markup (JSON-LD, Open Graph, Schema.org microdata)
• Manual element picker for sites the auto-detector doesn't cover
• Configurable check interval (default: every 60 minutes)
• Per-item price history
• Badge counter for unread price changes

Privacy: no accounts, no remote servers, no analytics. All data stays
in your browser's local storage.