RedMorph Yeti is an ad and tracker-blocker which also enables selectively blocking internet access by certain apps.
Basic ad and tracker blocking works much like RedMorph's browser extensions. You can leave the app to work automatically and block almost everything, drop the protection globally if you see problems, or adjust it by site (no blocking here, full protection there).
RedMorph Yeti additionally displays the permissions of your installed apps and enables controlling what they're able to do online, doing anything from blocking access entirely to preventing specific activities only.
RedMorph also includes SpyderWeb, a graphical visualisation of the various domains your current site is trying to access. These might be subdomains of its own, maybe a CDN, but you might also find ad sites, trackers and more. This doesn't have any great practical value, but it's sometimes interesting to see how much a page is trying to do behind the scenes, and all this extra activity might also explain site performance issues.
RedMorph Yeti is free as we write, but this is for a limited time only. After that it'll be priced at $4.99 per device.