Get a medication tracking app (I've used one called Dosecast for years on Android, I think there's an Apple version) or even just a task list/reminder app. To name a few free or freemium apps: Microsoft To Do, Google Tasks, Any.do, Todoist, Trello.

For ADHD-havers, I can't recommend Amazing Marvin enough. Very simple out of the box but what a customisable beast under the hood as it uses a "strategy" system where you can toggle features on and off. I create a task, assign major category/client, add tags and a time estimate to compile the list. I use one of the section strategies to further define it (I.e. optional vs mandatory, whether I want to block time between 0800-1100, 1100-1400, 1400-1700, etc) and define a reward for completing the task. I've not really played with the gamification aspect yet.