After a lot of years of struggling with finding the best system for myself, the best app and combining couple of different software, I've realized that it's more about simplicity, adopting the concept that works best for you and sticking with it for an extended period of time.
It's also a lot about discipline. People don't need an app to tell them that they should do the work and not play games for hours. Most of the time they are disorganized and procrastinating because they don't have the discipline and the drive, and not the lack of system or an app for time management.
The best advice I can give you is to just experiment with a bunch of shit to see what works the best for you. Try it, see if it works, dump if it's not clicking with you, and stick with what pushes you forward.
What I apply for myself:
-Notion - This was a real game changer for me personally. I love the simplicity of it and I have everything I need to organize every aspect of life and business. A lot of people swear by Evernote, but for me, it just didn't work. I ran into Notion a couple of months back and it literally changed the way I organize myself. Notion syncs up across all of my devices and holds information related to every one of my businesses perfectly organized, and other aspects of my life like shopping lists, to do lists, monthly and yearly goals etc. I also use an extension on my browser to save up articles into Notion that I can read later.
-Google Drive - For all files and docs, I use Google Drive unlimited storage. It syncs up well with Notion and with the combination of 2, there's nothing in my life or business that I can't manage and don't have covered.
While this system works really well for me, it may not be the best solution for others. With this system, I also apply a set of habits that really pushed me forward in life:
-Planning my day the night earlier - This is probably one of the better things any person can do. It works really well for me because I clear up my mind and can go to bed knowing that I have my next day planned out. I also wake up knowing exactly what I should be working on, and in which order.
-Heavy load first - In the first few hours of the day, you are naturally going to have the most energy, therefore use that to your advantage. I focus on getting the heavy load out of my way. I also get a psychological boost from getting the hard shit done and I don't keep those things on my mind bothering me while I knock down the other tasks of my list.
-Brain dump - I try to keep my mind free to focus on the tasks at hand, so I also use Notion to throw in every idea, thought and even journal when needed. I try to always keep my mind clear, so if I know that I need to buy some shit or do something, I want to record it Notion and know I can forget about it and rely on the software to keep that information stored.
-Knowing when to push and when to let go - not sure if this can be counted as a habit or what, but throughout the years of working for myself and only having myself to rely on, I believe I developed a feeling of knowing when I need to push myself and my boundaries, and when I need to step off the gas and just enjoy life. Sometimes a to-do list can be ignored, not everything needs to be perfect, and I can just do other shit I feel doing.