Obviously we are partial to PiCal, since it's our baby. However, one app can't do everything, and there are several others that have made our lives significantly easier, and some keep coming up in conversations with our users. These apps haven't necessarily been designed for ADHD specifically, but they address problems that can come up when you have ADHD. Especially if you have dyscalculia, or problems with time blindness, remembering and keeping track of things. We have no affiliation with any of these, we just use them.
Pretty Progress for visual deadlines
The nicest visual countdown app we've found. We use it for those really long term deadlines you need to remember for bigger projects, or deadlines that interrupt usual workflow, like vacations or holidays. Having the widgets on the home screen is a great glanceable reminder of when it's really getting time to knuckle down and make sure certain things are done.
Things for ToDos
A really clean todo list app, with the ability to quickly send a todo into the future so if you're not doing it today, it will reappear on a day when you're more likely to do it. Also works well with the Getting Things Done method. We like to add emojis to project names so it becomes more visual.
The only downside of Things is it doesn't sync with your calendar. Todoist supports calendar sync, however, which means you can see those todos in PiCal as well.
Hey.com for email
This alternative to email has a lot of really uniquely helpful features, like the ability to move emails with important but unactionable information to a "pinboard" for later reference, or to a "reply later" collection. It's also super easy to screen out emails that you don't want, which really helps sort out the clutter. You can also add notes to an email so when you're scrolling through your inbox you can leave your future self a summary of what you need to do about its contents. And you can schedule emails to reappear in your inbox at a later date so they're out of your way for now. And so much more. Definitely worth checking out.
Bonus: Flowlab.io for coding games
This is more a delightful discovery than a productivity app, but really worth a look if you tend to be more of a visual learner and numbers/letters don't "stay put" for you. Web-based visual code as flowcharts instead of blocks! No need to remember syntax, information just flows from one node to another via "wires" that you draw. And when you're done, you can export your game to any platform. Approachable and fun.
Bonus: explorabl.es for exploratory learning
A collection of visual, hands-on explanations of a wide variety of things, guaranteed to send you down a bunch of fascinating rabbit holes.