Nice, there's also ble.sh -- a bash replacement of readline that has zsh/fish-like syntax colors and completion. It is actively developed and the maintainer has implemented 2 features I've requested in a matter of hours.

If you want to check it out: https://github.com/akinomyoga/ble.sh

(Still, I personally believe these features are overrated and don't actually bring in more usability or comfort to the command line experience. For instance, ctrl+r kills the need for suggestions and instead of selecting files scrolling through them with your fingers, you can select them using your eyes?)