QR reader/writer: it’s pretty easy to make a malicious QR code reader, so I made my own. Works offline, like on an air gapped computer.
Secrets: split up a secret into N pieces so you can recover it with any M of the pieces
Mosaic Web Dev: a platform for hosting lessons that students can go through at their own pace. A solution to teaching technical summer camps where half the class got left behind and half the class felt bored (and my voice got tired).
HumanSort: sort a list based on whatever you want by comparing two things at a time