Diff-IE is described as 'prototype Internet Explorer add-on that highlights the changes to a page since the last time you visited it and enables you to view and compare previously cached versions of the page' and is an app in the OS & Utilities category. There are more than 25 alternatives to Diff-IE for a variety of platforms, including Online / Web-based, SaaS, Windows, Firefox and Self-Hosted solutions. The best alternative is UptimeRobot, which is free. Other great apps like Diff-IE are Update Scanner (Free, Open Source), FiveFilters Feed Creator (Freemium), Feedfry (Freemium) and DELTAFEED (Freemium).
Dashboard with 50 Monitors, Checked Every 5 Minutes, Totally Free. Monitor HTTP(S), Ping, Port and check Keywords. Get alerted via e-mail, SMS, Twitter, web-hooks or push. View uptime, downtime and response times.
Monitor webpages: Get Newsfeeds from web pages that do not deliver RSS Customization: Monitor portions of webpages via CSS selectors / ignore Ads and Social Media Elements Handling: Manage your monitorings. Get them via RSS or e-Mail
GitHub-powered open-source uptime monitor and status page. Monitor uptime every 5 minutes Using GitHub Actions, monitor unlimited webpages every 5 minutes, and store version-controlled response time stats.