Block tumblr ads in app
https://adguard-dns.io/en/public-dns.html
On Android, (if your device supports Private DNS by default) just find these options on your device, otherwise try using their app.
Settings > Networking > Private DNS > specify "dns.adguard.com" and save
iOS blocking is not as robust I believe, either download their app or use the link above to download a Profile which will update your DNS settings to use AdGuard
Otherwise, setup Pi-hole and/or AdGuard Home for your home networking (WiFi) DNS.
You can use a VPN like Wireguard or Tailscale to be able to block ads when you're using mobile data out-and-about by connecting back home to block them










