Blocking trackers on your phone
On a phone, the apps are the leak
On the desktop, tracking mostly rides through the browser, so a browser blocker goes a long way. On a phone the picture is different: a large share of tracking happens inside apps, which can carry their own advertising and analytics code that a browser extension never sees. Reducing mobile tracking therefore starts in the operating system, not in the browser.
The two highest-impact settings cost nothing and take a minute. Reset or disable your device's advertising identifier — the per-device tag that ties your activity across apps together — and review app location and tracking permissions, denying anything a given app has no real reason to need.
Adding network-level and browser blocking
Beyond the built-in settings, a DNS-based or on-device blocker can stop connections to known tracker domains across all your apps, extending coverage past the browser. This is the closest a phone gets to whole-device blocking, though it cannot inspect encrypted in-app traffic in detail.
For web browsing specifically, a content-blocking browser or blocker still adds value on top. Layer these by effort: change the free built-in settings first, add network-level blocking if you want broader coverage, and use a private browser for the reading you do on the web.