I was always amused, when people told me they have some apps installed, that block or limit their usage on their smartphones, to force themself to stay away from the thing and take a closer look at the world around. My answer was: "Just do it, why do you need a technical solution for that? It's a decision, it's your own will and intention... just turn it off".
But the gruesome reality is, that it sometimes doesn't work, because smartphones are always around us and to be more precise: the WWW. You can surf around, swipe through Instagram, read the news or emails, listen to music and so on. Just reach to your pocket and with a small touch you are online and part of the digital jungle. Music is okay, reading some digital books too, but I watched myself and tracked the pages and the time, that I spent on them and also how often I opened one of them. And after two weeks it was really surprising, how MUCH time I invested in "just reading some news and websites".
I'm using Firefox on my Android phone and so I installed "LeechBlock NG". You can block specific websites by default, but much more interesting: you can set a time for specific sites or groups of sites. So I set the timer to two minutes for the news pages and it's really interesting... because it works. There is a small timer visible in the corner of the pages, so I know, that I don't have too much time to read every single news header (most crap), so I read just the important ones and then, after the timer reaches zero, the pages get completely blocked for minimum 4~8 hours, depending on the category.
And the reality is, that I don't miss anything, but now avoid to visit the pages multiple times for "nothing" or to read the same stuff twice, because there is nothing else to do (example: waiting for the bus).
It leads to some other behaviors, because I started to reduce the smartphone time or read more books on it, listen more audio books or just music sometimes. Finally I reduced the crap time from ~two hours a day to ~fifteen minutes. With the time blocker function, I don't have the feeling, that I block myself or lose any information, but I try (automatically) to (have to) be more efficient with my smartphone time.
And yes, for sure, I also got rid of a lot of other, unnecessary apps, but also old stuff like hundreds of photos with "whatever" and many other things. My smartphone handling feels now again more like a "useful tool", that supports my daily life with nice features like emails, weather, calendar and so on and not as stupid, brainless time gap compensation with meaningless news, photos, comments and other stuff of silly content waves.
I'm still a fan of "just use your brain to focus and don't use external support", but this tiny, little add-on does it well and has improved now my smartphone time. In addition I also use more and more "Violoncello" for blogs, which is a text based browser for Android. Very simple and you have to surf the WWW without images, java script and other things, but it's enough to read interesting entries and thoughts or knowledge things and it also supports tabs and bookmarks. That is enough.