Most of what I know outside iOS, I learned from side projects. By side projects I mean the things you build outside your job or school: sometimes for fun, sometimes because something annoys you, usually to learn something.
At work you tend to use the same stack and solve similar problems. A side project has no deadline and no one to approve your choices, so you can try a new framework or a whole new area without pressure.
My day job is building iOS apps with Swift and UIKit. I wanted to understand how the rest of the software gets built and delivered, so I started doing web projects on the side, frontend and backend. Working with React, Next.js, Node.js and databases showed me how the pieces fit together, and it made me a better iOS developer too, because I finally understood what was on the other side of the APIs I was calling.
I've also used side projects to try iOS frameworks I don't touch at work. I built things with MapKit to learn maps and geolocation, and played with SpriteKit to see how game development works. None of that was for a ticket, but it all came in handy later.
And they're yours. You pick the goal, the tools and when it's done. You can share them, use them in your portfolio, or keep them as a place to experiment. When you get stuck there's no one to ask but the docs, so you get better at figuring things out on your own.
If you've been thinking about starting one, pick something small that you'd actually use.
Here are some of mine from when I wrote this:
Ritus Club
A site about specialty coffee, with guides, recipes and an ebook in Portuguese. I started it because I couldn't find the coffee reference I wanted when I was learning, for baristas, enthusiasts or anyone curious.
Solitude Space
A focus app in the browser: todo list, notes, a Pomodoro timer and ambient sounds, with no account. I use it for long blocks of deep work.
Readme Builder (Browser Extension)
A browser extension that helps you write and clean up README files without leaving the browser.
UPDATE (06/27/2026): A lot has shipped since this post: Noira Cam, the TabNews app, and more. Check the full catalog on /apps.