There is actually an official iOS app for Mastodon written in Swift. So you are fortunately not locked out from this social media platform. Mastodon is an interesting project, because it is decentralized. It means no corporation can control what is published. You just choose a server/s you want to join, and can explore the new way for… mastodoning, I guess.
Sometimes you’d like to set up a rule based proxy on Mac. If you do, ClashX (written in Swift) is a Clash (written in Go) based project to do just that. It supports HTTP/HTTPS and SOCKS, offers GeoIP rules, Vmess, Shadowsocks, Socks5 and Trojan. It comes even with Netfilter TCP redirect support.
Code App tells it all. To make it easier to code on the iPad devices, the Code App is developed in Swift. The looks of the app can be familiar for you. It is not a coincidence, because the developers inspire it on the VS Code design template.
Currently, it comes with built-in Node.js, Python, C, C++ and PHP runtime. Added, the text editor is based on VS Code Monaco Editor, it supports nicely local file-system, includes emulated terminal, Git version control, and popular package managers (Pip and NPM). It’s a great solution if you want to code on your iPad tablet.