As I’ve written many times, one of my most used and useful packages is abo-abo’s Ivy/Counsel/Swiper suite. Happily, he is always tweaking it, making it better with each iteration. He latest tweak rethinks the reverse i-search command (Ctrl+r) used in Bash. The problem, he says, is that you have to invoke Ctrl+r repeatedly while you search for the command you want.
Abo-abo applies the Ivy UI to this action so that you get a list of possible completions that can narrowed in a fuzzy manner. That’s great for when you’re in shell mode but abo-abo, of course, brought the functionality back to Emacs itself so that you can, for instance, use it when opening a file with counsel-find-file.
The updates are already in Melpa so if you’re up-to-date with your packages, you can start using the functionality immediately. You’ll need to set a couple of key bindings but that’s all. Take a look at abo-abo’s post for the details of setting things up.
As I’ve written before—most recently here—if you haven’t yet tried Ivy/Counsel/Swiper, you owe it to yourself to give them a try. Different people like different things, of course, but it’s hard for me to see why anyone wouldn’t like the Ivy/Counsel/Swiper suite. Helm users have basically the same functionality but Ivy and friends are a bit lighter weight and at least one Helm user that I know of switched after trying Ivy out.