https://junegunn.github.io/fzf/
Okay, this seems pretty useful for anyone using a command line. It can go in Unix pipelines (or backquotes) and you can interactively invoke it if you set it up for that. It has an option for a file preview as well. It's going to take some retraining to get use to it, but I installed it first in a low memory RPi clone and it's working great in Armbian.