CodeGrape
CodeCanyon
Codester
Theme Forest
99designs
Creative Market
Sell My App
Sell.app
RPG Maker
Godot Engine
GDevelop
Unreal Engine
Unity
Stencyl
Adventure Game Studio
MonoGame
CodeGrape
RPG MakerCodeCanyon - Scripts and Snippets From $1 for PHP, JavaScript, ASP.NET, CSS, Plugins, HTML5, Mobile and more
Godot Engine - Feature-packed 2D and 3D open source game engine.
Codester - The marketplace for ready-to-use web development assets
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Theme Forest - The #1 marketplace for premium website templates, including themes for WordPress, Magento, Drupal, Joomla, and more. Create a website, fast.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.