Polyoptra is a multi-site dashboard for agencies and site owners. It combines GA4, Search Console, real-visitor page speed, uptime, SSL and domain-expiry monitoring in one grid, with alerts when a site's tracking has gone dark. It also offers a weekly summary email, branded client reports and read-only share links.
There is a free plan for 3 sites. Paid plans start from $24 a month, priced by the site. The Agency plan has a 14-day free trial with no card required. It is a web app.
Checking GA4 across dozens of sites means tab-hopping, and a broken tag just looks like a quiet week. Polyoptra was built to show every site on one live grid and flag the ones that went dark.