Ask HN: What personal tools are you the most proud of making?

I kept coming up with project ideas but never properly followed through on them, and then I realised that it's because I'm creating tools for 'other people'.

Of course, 'other people' is a very vague audience to create for. The most prolific devs I know create amazingly crafted tools for themselves, and if these tools grow, they make it for others.

So what are some tools you're really proud of making for yourself? Bonus points for projects that are real labours of love.