Alternatives to Arena Chess GUI
Veteran free GUI for running 250+ chess engines. If that's not for you - or you want to try something different - here are apps that overlap on features and use cases.

Scid vs. PC
Steven Atkinson and contributors
Open-source database and analysis powerhouse.
Free
Windows · macOS · Linux

Chess.com
Chess.com, LLC
The default home of online chess.
Free · from $4.17/mo
4.5Web · iOS · Android

Stockfish Chess
Stockfish contributors (app by Daylen Yang)
The world's strongest engine, free and open source.
Free
iOS · macOS · Windows

Forward Chess
Forward Chess, LLC
Interactive chess ebook reader with embedded engine.
Free
4.8Web · iOS · Android

Chess Position Trainer
Stefan Renzewitz
Veteran flash-card repertoire trainer for desktop.
Free
Windows

Lichess
Lichess (charity)
Free, open-source chess. Forever.
Free
4.8Web · iOS · Android

ChessBase
ChessBase GmbH
The professional's database and analysis suite.
From €199.90 one-time
Windows · Web · macOS

Chessnut Air
Pendo Technology Ltd. (Chessnut)
Affordable electronic board with multi-app support.
From $249.99 one-time
2.6iOS · Android · Windows