Best apps/sites to kill procrastination?

On Android, turn on developer mode and set the color scheme to monochromatic (black and white)

I use LeechBlock on my browser to set a maximum time I can use some websites, according the day, hours... (typically restrict myself to go too much on news site during the day)..;

A friend of mine said he'd send me a link. Doesn't seem to have gotten around to it yet.