i know im the same ive started using an app called brain focus it helps a bit to get things done and stay on taskssubjects i also started writing things down to get them out of my head just any random thing that pops up so i dont keep circling back to it but dont completely forget it either i use an app called life diary for that though i dont think its specific for that i like the its lay out i use it for everything from a to-do list to random subjects i wanna check out to write down deeper thoughts  i dont know if there are better apps out there that specifically are targeted towards people with adhd that would be really nice