AudioNodes - Modular audio production suite with multi-track audio mixing, audio effects, parameter automation, MIDI editing, synthesis, cloud production, and more.
Discord - Discord is a free voice and text chat client for gamers and non-gamers alike. You can use it from your browser and it's available on iOS, Android, Windows, Mac, and Linux.
Waow - Awesome WhatsApp Web Client to deliver you the best WhatsApp experience.
Compression
7-Zip - Open source Windows utility for manipulating archives. Formats 7z, ZIP, GZIP, BZIP2 and TAR are supported fully, other formats can be unpacked.
Search Deflector - A small program that redirects searches made from the Windows Start Menu or Cortana to whatever browser and search engine you prefer.
FreeOffice - FreeOffice is a complete office suite with a word processor, a spreadsheet application and a presentation program – all compatible with their counterparts in Microsoft Office.
LuaStudio - Free game development tool/engine. Create games and other graphic focused apps on Windows using Lua/LuaJIT programming language. Export them to many platforms including iOS, Android and Mac.
Steam - Largest online video game retailer. Desktop app allows you to organise your library of games and play them at any time. But you already knew that.
Unity - Free game engine. Easy to pick up and use with a number of tutorials.
Unreal Engine - Another free game engine. Lots of documentation and easier to pick up, but you pay 5% royalties to Unreal when you make money from UE-based games.
Everything - The fastest file/folder search tool by name.
Executor.dk - A free multi purpose customizable and light-weight launcher.
f.lux - Automatically adjust your computer screen to match lighting.
Inkdrop - The note-taking app for Markdown lovers.
KatMouse - Utility that enables "universal scrolling" in Windows: scrolling does not need the window to be active/clicked first (i.e. how it works in macOS and Linux)
Keypirinha - A fast launcher for keyboard ninjas on Windows. You can think of Keypirinha as an alternative to Launchy and a cousin of Alfred.
Acrosync - The only native rsync client for Windows (no cygwin required). It supports automatic uploads on file changes and incremental hourly backups.
AddToSendTo - This script lets you add your favorite Folder to Send To option, when you right-click.
Advanced Renamer - Advanced batch renaming program, with support for renaming based on GPS data from images, ID3 tags from music files, TV show data and regular expressions.
Carnac - The easiest way to record keystrokes during any screen recording.
HWMonitor - A hardware monitoring program that reads PC systems main health sensors : voltages, temperatures, fans speed.
IrfanView - A very fast, small, compact and innovative graphic viewer for Windows.
LICEcap - Animated screen captures and save them directly to .GIF
Process Explorer - Discover which program has a particular file or directory open. Process Explorer shows you information about which handles and DLLs processes have opened or loaded.
LightBulb - Reduces eyestrain by adjusting gamma based on the current time
Sysinternals Suite - Tool suite by Mark Russinovich that provides access to Windows internals for troubleshooting: processes, physical ports, disk activity etc.
Unlocker - Unlock files Windows won't let you delete
Waltr - Transfer any movie or music file to your iPhone w/o iTunes.
WinDirStat - It is a disk usage statistics viewer and cleanup too.
winreg-cli - Command line tool with a fluent API for modifying Windows registry.
WizTree - Excellent, small utility application allows users to quickly find large files on a hard drive.
ZoomIt - It is a screen zoom and annotation tool for technical presentations. It runs unobtrusively in the tray and activates with customizable hotkeys to zoom in on an area of the screen, move around while zoomed, and draw on the zoomed image.
Video
HandBrake - High performance video encoding and conversion tools with a nice GUI.