you find some of them in the reapack repos

https://github.com/Toxyl/sonica-bundle  (some tools for mixong and mastering and mangeling)

https://github.com/indiscipline/awesome-reaper  (curated list of stuff around REAPER)

https://github.com/Buy-One/REAPER-scripts (stuff)

https://github.com/leafac/reaper (Leandro Facchinetti’s REAPER Effects and Scripts )

https://github.com/DocShadrach/MyReaperScripts (REAPER Scripts Collection by DocShadrach)

https://github.com/edkashinsky/reaper-reableton-scripts/tree/master (ek. scripts | This scripts makes Reaper a bit close to Ableton workflow. Also it brings useful things to save time.)

https://github.com/michaelpilyavskiy/reascripts (Lua and EEL scripts for Cockos REAPER written by Michael Pilyavskiy.)

https://github.com/reateam/reascripts (ReaTeam Scripts Repository)

https://github.com/JoepVanlier/JSFX (JSFX)

https://github.com/Reaper-Tools (don't know if this it of real value)

https://github.com/mharchik/ReaperScripts ("This is a collection of scripts that I've created for Reaper. They are mainly focused around my game audio workflow designing individual assets.")

https://github.com/acendan/reascripts (Aaron Cendan's ReaScripts for REAPER)

https://github.com/justinfrankel/reaper-sdk (This is the REAPER C/C++ extension plug-in mini-SDK )

https://github.com/cfillion/reapack (ReaPack: Package manager for REAPER)

https://github.com/iliaspoulakis/Reaper-Tools/ (This is a collection of various tools I created to enhance my workflow in reaper.)

https://github.com/TeamAudio/reaspeech/ (Painless speech-to-text transcription inside of REAPER)

https://github.com/audiokinetic/Reaper-Tools (Audiokinetic Reaper Tools Repository)

https://github.com/bsmith96/Reaper-Scripts (BSmith96 Scripts - ReaScript , These scripts are largely designed for a live sound workflow )

https://github.com/junh1024/Reaper-Surround (Reaper-Surround , A collection of mostly surround JSFX for the REAPER DAW)

https://github.com/MathieuCGit/Reaper_Tools (Reaper_Tools , Some scripts for Reaper D.A.W. , ReaCAT - Reaper Chord Adding Tool)

https://github.com/StephanRoemer/ReaScripts (Stephan Römer's scripts for Reaper)

https://github.com/davidhealey/reascript (Dave's Reaper Stuff , "This is the place where I will upload various additions I make for Reaper for my own personal use that I wish to share with the community."")

https://github.com/BuriedStPatrick/reaper-ui (Reaper UI, An Angular Material based web-UI client for the REAPER DAW.)

https://github.com/topics/reaper-scripts?l=c%2B%2B&o=asc&s=updated (a list of repos . )

https://github.com/DemianDeVante/Reaper-RPC-Control (RPC Control and Scripts for Reaper DAW)

https://github.com/EmmanuelBeziat/reaper-web-live (reaper-web-live , Web interface for the DAW Reaper, to use in a live context.)