In all seriousness, phar-updater is my implementation of recommendations I made in a previous blog post around self-updating PHAR files. Those recommendations were, predictably for me, largely concerned with self-updating from a security perspective. Implementing it brought ease of use and flexible integration to the fore also. It can be surprising what a little extra work, testing and packaging can accomplish for reuse compared to throwing code into one file and calling it a day. It's been integrated into Humbug with nary an issue.
The package makes it simple to integrate the self-update functionality into your existing phar package deployment including updating running versions, enforcement of TLS connections and allows for configuration of updates based on version numbers. You can see his own example in his Humbug package's "SelfUpdate" class.