If you’ve got a bit of computer knowledge, a Raspberry Pi (or other means of running a server), and a little time of your hands, and want to block many of the ad servers and trackers which watch your browsing without installing anything on your devices, take a look at Pi-Hole:
Unlike some other tracker blockers, this runs as a machine on your network, so you do not need to install software or configure apps on each end device, but obviously at the cost of needing to run your own server.
Neil adds: it was very easy to set up, but the default DNS settings were a bit surprising. I’d suggest setting its own DNS to your main DNS server, not just localhost, and I’d set your router’s DHCP config to fall back to your main DNS server if the Pi-Hole box falls over, for reliability purposes. Other than these oddities, I’m impressed with it so far.
Thanks to Neil.