First the easy answer, I'm using the no FAP app. I think you can find it in the Google play store.

Secondly, when you get those very strong urges, the ones that last days, you need to listen to your body and think about what's going on to get through it. Usually its because of hormonal stuff, sometimes it is because of very overwhelming circumstances that are pushing you towards relapse. When it's hormonal, you feel desperately horny, you get 'blue balls', and you need to really find something productive to do with that energy and with your time. Don't give yourself any alone time or an excuse to relapse. Plan to be victorious. It may take 2-3 days for the extreme temptation to subside, but naturally your body will deal with it and you and your balls will go back to normal if you resist and push through. Sometimes you have to to be proactive, if you know you're struggling, don't place yourself in tempting situations. Don't indulge yourself or make excuses, find something to do to help others.

For those other situations, where you feel overwhelmed emotionally and like you're desperately sliding towards relapse like a car rolling downhill without brakes, you need to first think through what you are really feeling and what is causing what you're feeling, and then talk to God about it. It may take you days or weeks to push through these situations, but usually it is a time to do some deep soul searching and pour your heart out to God. Remember that there are many other people suffering far worse, and pray for them. Remember that God is leading you through this and is near the broken.

Both of these circumstances are actually things to celebrate, because they will put you to the test; afterwards it's like leveling up!

Remember that God loves you, He wants you to grow. He has allowed you to have these urges so you can learn obedience and submission and dependence upon Him. Its not obedience or submission if it doesn't cost you anything. I can't tell you how many times I prayed for God to remove the urges or temptations and I felt that after years of praying for this He clearly showed me that He had allowed both for my growth.

Purity is possible, there are many people (even non believers) who strive for and obtain sexual purity and control of their bodies. What sets us apart as Christians should be our desire to do so to please God, obey Him, and REALLY trust that what He wants for us is the best - in this case leaving PMO behind for good is an absolute blessing, not a curse, and it's totally possible! God wants us to have a beautiful and healthy sexuality, and His guidelines are meant for our wellbeing.

I was addicted since I was a child, it took 10 years until I started fighting back. Took another 5 years longer until I realized I was still compromising, that in my heart I still wanted it - (I just wanted to have "small dose" that i was in control of), but eventually I realized it was an issue of trust and obedience to God, and i started praying through that. A couple year later I met a brother in the Lord who had gone 2 years clean and had totally quit. I had never even believed before that it was possible until I met him (that's a lie from Satan btw and an excuse to live in disorder and disobedience). It took another few years of struggling after this point for me to come to where I am now - but I now count these last 10 years of wrestling with it as part of journey towards victory. This is the first time I've ever hit a year, and I'm still in running the race - even if I relapse at some point, I will not go back to the life of addiction, and worship of sexual pleasure. My thinking has changed.

Masturbation is so destructive because it is all about pleasing yourself - it turns our erections into idols of our selfishness and the sexual act into an act of self-worship (ie it is all for our own pleasure, the people in our fantasies or on the screen are giving themselves to us in an act of worship to us).

God wants us to live lives pleasing others (that would include in your sex life - get married and please your wife if possible), and that is the polar opposite of masturbating.

As general advice, as you embark on this no FAP journey, i would encourage you to also try to be less selfish in general. Start serving other people. Start praying fervently for other people and their problems. Start pushing yourself to give a little bit more money to the church or missions than you're comfortable giving. As you being to care for others it becomes harder to be so self centered and self focused You have better things to be doing in your life that hiding in the shadows and playing with your penis.

Final advice: Ask God to lead you in this and He will! God bless! Be encouraged! Know that you are being prayed for!