You're never going to find an automated filter which can perfectly strip the bad away from the good and present an even remotely "better" internet than the one we have today. Time-based filters do not work, because the user's ability to override them will always outweigh any enforcement power the system might have, and a "nudge" isn't enough for most people. Even devices like the Litephone, or setting your phone's display to black & white, doesn't work in the long run; its more performative than minimalist, color is kinda important, the problem really isn't the phone, or the tools, or the filters, or the services; its you.
Saying "I just need a good piece of software to control my addiction to software" sounds insane when phrased like that; "I just need another cig to control my addiction to nicotine".
Devices like the litephone, or the recent frontpage post about the Apple Watch iPod case, are kind of missing the point; if you're going out to buy another device to address your problem with using devices, what you're participating in is performance art, not self-improvement. Did you see that the litephone 3 costs $800?! The most digitally minimalist people I know use full-featured smartphones; sometimes rather old, but still fully capable. They just use them far, far less. No one is telling you to get rid of Youtube, but maybe a homepage smattered with ludwig and asmongold videos indicates you have a problem.