Hal Sudsworth
Every fishing addon gives you a lure button and a catch log. R.E.E.L. gives you those, then clears everything else off your screen. Cast, and the interface fades out. Names, nameplates, combat text and tooltips go with it. Graphics go up. What's left is Forever's water, your bobber and one small bar with exactly what you need. We removed everything. Except your fishing line, you'll want that.
For World of Warcraft: Forever only. Free.
Install from CurseForge or Wago, or drop the Reel folder into Interface\AddOns. Type /reel. The toolkit is on by default; pick a preset on the General page (Just the bar, Clean, Full immersion) and tweak from there.
Open an issue on GitHub. Before you do, type /reel debug in game and then /reload; that writes what the client reported about your fishing skill, lures and buffs into WTF\Account\<account>\SavedVariables\Reel.lua. Attach that file to the issue along with any error text, and say which preset or toggles you had on.
After launch. The beta client is gone and the live one isn't here yet.