Some advice to help put the phone down.

Delete all social media apps. They are built to be addictive. If you can't have a healthy relationship with them, delete them and maybe a week or month later reevaluate if you need them.

Put your phone in greyscale or black/white mode. This one will sound odd, but your brain is so much less interested in constantly being on the phone in grey mode. Plus it's a visual reminder to not be on the phone too much.

As for apps to help, I do not have any good apps for productivity. I just use goodreads to keep track of what I am reading and what I plan on reading. I try to write a review of everything I read just to help others, but don't go overboard into the social aspect of the app.

Check if your local library has overdrive.

If so, I would highly recommend getting a kobo as it pairs very easily with overdrive. Then you don't have to worry about buying books as you can rent them from the library, and only buy the things not on overdrive. (overdrive has quite a large selection)

Also just a library card will get you access to tons of physical books too