wmfocus VS xorg-choose-window

I think wmfocus (Github, Arch) should be what you are looking for. It describes itself as "heavily inspired by i3-easyfocus."

I use wmfocus to switch my floating window efficiently.

I've searched around for similar tools (and this has been asked in the past in other places: https://unix.stackexchange.com/questions/368825/select-x-windows-using-the-keyboard-like-ace-jump-hint-following-or-similar). The only tools I've found, in addition to XMonad's EasyMotion, are https://github.com/loki42/easyxmotion (mentioned in the stackexchange link) but after some quick and dirty hacks of the code (which is way over my head) I was not able to get much larger fonts nor obtain the window ID. There are also two tools that work with i3: https://github.com/cornerman/i3-easyfocus and https://github.com/svenstaro/wmfocus . Both give window's IDs and the last one displays large fonts with a small square background, so hints have great visibility. Both should, in principle, be window manager agnostic (https://github.com/cornerman/i3-easyfocus/issues/3 , https://github.com/svenstaro/wmfocus/issues/4 ), but those issues for WM-independent implementations are still open and the only existing implementations are for i3. (I played with both and looked at the code, but removing the i3 dependencies was not obvious to me ---and wmfocus is Rust, which I've never dealt with before).

I use this one: https://github.com/svenstaro/wmfocus

I've modified xorg-choose-window so that: a) the overlays only cover a small fraction of the window, so the window's contents are visible; b) a larger (but much uglier) font is among the commented out options you can try. Code available from https://github.com/rdiaz02/xorg-choose-window/tree/smaller-overlay (branch "smaller-overlay" of my fork of ikn's xorg-choose-window: https://github.com/ikn/xorg-choose-window).