Seem that a new version of app-misc/devtodo is out (since 2011), called nicely, version devtodo2. There seems to be a release tagged as 2.1 on github (https://github.com/alecthomas/devtodo2), but as it is quite old, maybe a live ebuild would be better. Reproducible: Always
Unfortunately, devtodo2 looks more like a separate project. The original is written in C++ and the version of which you speak is written in Go. I'd recommend that that we make this a new package. This should probably wait until golang-build eclass is finished. https://archives.gentoo.org/gentoo-dev/message/bf23b91d09953eb663505a6bef248329
cc'ing williamh in case he is interested in writing/maintaining the ebuild