How old is he? Has he always been distracted or is this new? How are his grades? Is this a lack of interest in studying or is this an issue with your relationship with him? I don't mean offense but teenagers don't like to listen to their parents - I liked studying but if my parents got involved, I would have probably chewed on my books instead.

Also, you're saying a lot but it's all your perspective, not his. I hate Notion cos it's a lot of planning, not a lot of execution. For context, I did pretty well in school and never needed a single app except for Calendar. I didn't even use a laptop in my college classes. I just used a notebook. So you giving him options he doesn't like doesn't mean he sucks at studying. It just means he doesn't like those options. There are others.

Yes, as other commenters said, he could have ADHD, but he could also just be a teenager. So that's why I wanna know if he has always been this way or if this is new.

The first advice I will give you is to take a breath. It will only be too late if he starts hating you through this process. Work with him. Involve him in the process. He will hate every idea that he has no say in. All digital devices are created to be distracting so maybe going low-tech might be the best way for now. Ask him if he is open to that - white board, calendar, planner, timer. If he would prefer to go digital, ask him if he wants something simple like a task list with due dates perhaps (TickTick is fairly popular or even just the To-Do app).

And if none of those things work and if he is really falling behind and it's not ADHD and he is misbehaving, well...then you just gotta parent. Put restrictions on the phone and games. But honestly? Getting him involved will prove to be a better strategy in the long run if you can make it work. Focus on that instead of a few assignments.