iOS: There are thousands of to-do apps on the iPhone and they're all just slightly different from each other. If you're looking for something that combines the "fun" of an app like Clear with simple, colourful categories for organisation, Tick is a to-do app that's worth a look.
Tick allows you to create a custom home screen with different icons that work as lists. Tap a list, and you get your to-dos in that category. It's incredibly simple and easy to use, and unlike Clear it's not a pain to navigate between different lists. Tick also has a few clever tricks up its sleeve, including being able to AirDrop lists between devices and an automatic dark mode. If you're looking for something a little brighter from your to-do app, Tick's worth checking out.