Send as POST is an extension for iOS and macOS that allows you to send a POST request to share images and web pages. It's open source and available on the App Store. It's also what I use to post photos and links to this site.
Beeminder is a tool for fighting akrasia - in other words, making yourself do the things that you want to do. I write the iOS app and a bunch of other code when Bethany lets me.
A simple to-do list iOS app that charges you for not Getting Things Done, via its integration with the Beeminder API.
A spontaneous adventure generator for iOS.