[paulz_]

Firefox on android has support for ad blocking extensions. I removed reddit's app and blocked it in the browser (having an adblocker on mobile is glorious by the way). You could do the same with hacker news and youtube. Then, when you want to use them you can still open it up but it's one extra annoying step to select "temporarily allow" when trying to visit it.

I found it was really effective for cutting back on reddit but still being able to use it occasionally as needed.