Unfortunately I lack a smart phone and data plan so I have never been a mobile browser.
I tried installing a filter in Chrome, but I always ended up either just going around it or simply pouring my time into something else online (YouTube, 4Chan, etc.). It was like playing whack-a-mole. I would block a site only to have this sort of nervous itch to browse. It didn't matter what I browsed, it just has to be online and distract my attention form whatever was at hand.
I spend an unhealthy amount of time online, probably 7-10 hours a day during the week and 15-20 hours during the weekend. I feel like it is a serious handicap. I find it really hard to apply myself for any significant length of time. for me, doing homework or studying for a test before 9:00 pm the night before is almost unheard of. As a result, I often stay up until 2:00 am or later doing work only to wake up at 7:00 or 8:30 am the next day. I have tried so hard to stop, but at times it really feels like I can't.