I am a firm believer that the only true way to quit porn is to change your underlying psychology.

Porn blocker applications on your computer/phone are a joke. You will circumvent them because you still want to watch porn. You must eliminate the desire to watch porn through greater understanding of the issue, and addiction psychology. That way being porn-free will be as effortless as not drinking poison every day, or not wanting to shoot yourself in the head.

Your Brain on Porn
You already know about this one... right?
You can swim around in an overwhelming number of studies supporting the harmful nature of pornography in the the research section.
One of the best places I can't recommend enough is the rebooting experiences section. If you need a garden hose of motivation to quit this disease, there's no shortage of people who have written emphatically about how their life has improved on here.
The EasyPeasy Method (free book)
This is one of the most important books I have read.
Contrary to how it is advertised, The EasyPeasy Method may not work immediately. It didn't for me. That's ok. Let the book plant its highly important seed of an idea in your brain. The book will win eventually.
Step one is to be aware of the core message of the book - that there is no genuine enjoyment in porn. And that quitting is a rational choice you can make when you become aware of the reality around your porn use.
Over time the knowledge from that book will begin to feel self-evident. I felt like I had read the book but didn't fully internalise it until a year later, realising that the book was right all along. It's important to have ideas such as those in The EasyPeasy Method in your brain so you don't succumb to weird defeatist thought patterns.
The Freedom Model for Addictions: Escape the Treatment and Recovery Trap
This book essentially contains the ideas in The EasyPeasy method, but on a more scientific level and from the perspective of a professional who helps people deal with addictions in a clinic.
The book breaks down why the ideas of traditional mainstream addiction psychology fail to work and deliver results for most people, hence 'Escape the Treatment and Recovery Trap'. The book teaches addiction science, hypersensitisation, and gives you the tools you need to make a choice. It emphasises that we always have the choice, rationally over whether we decide to use a substance, or porn, or not.
Highly recommended.
The Flying Eagle Method
I think this and The Easy Peasy Method are first cousins or something. The page above has many useful definitions and summaries of concepts around porn addiction that is important for you to understand.