use "Adguard" apps. This is most reliable ads blocker for your phone. It filters different ads from your screen. It is very useful and i get good result from this. I used many adblocker apps. Most of them are useless. But this is quite helpful for blocking ads
The VPN service I use blocks ads, but I don't always want to run my devices through a VPN, especially when I am at home. I used to root all of my Android devices but I am past that now--it's not worth the bother. Chrome supposedly is going to start blocking ads in the future, but I don't know if that carries over to the mobile version or not, and to what extent. Since I have so much synced in Chrome, changing to another browser isn't going to happen. Don't want that clutter on my phone either. I keep only what I need on each phone and tablet, and dump the rest.
Someone who can block ads without needing root would get a ton of downloads. Sadly it's difficult to make happen.