These are some of my favorite tool as a Postgres DBA.
I will update this list from time to time as I am inspired to do so.

Notepad++
This is my go to tool for text processing.
In addition to the top notch editing capabilities, some of my favorite features are:
– The Find in files search capability for when you need to find that script where you did that thing;
– The compare plugin for when you need to find that one difference in a million lines of text;
– The JSON Viewer for when you need to convert that big ugly JSON string into a human readable form;
Plus much more.
Notepad++ is free. If you find it useful you can (and should) donate to the project.
Downloads can be found at: https://notepad-plus-plus.org/downloads/

7-Zip
A simple yet powerful file archiver/compression utility that integrates well into Windows Explorer.
7-Zip is free. I have not found any way to donate or support the project.
Downloads can be found at: https://www.7-zip.org/download.html

Aqua Data Studio
This is a database centered IDE that supports multiple DBMS platforms.
My favorite feature is the ability to switch databases/servers within the query analyzer without opening a new window and copying over your query.
Aqua is NOT free. If you can convince your boss to spring for a license the productivity gain will be worth it. (in my humble opinion). You can get a free 14 day trial here: https://www.aquafold.com/aquadatastudio/trialregform/

DB Fiddle
DB Fiddle is an online SQL database playground for testing, debugging and sharing SQL snippets.
DB Fiddle supports PostgreSQL, MySQL and SQLite.
Basic DB Fiddle usage is free. The Pro option provides some additional features and is currently available for $7 per month.
Check it out at: https://www.db-fiddle.com

LibreOffice
LibreOffice is a free and powerful office suite, and a successor to OpenOffice.org (commonly known as OpenOffice).
If you’re running a lean operation and a subscription to those well known office tools is a challenge, LibreOffice can be a good alternative. It is compatible with documents created with other office suites. Its clean interface and feature-rich tools help you unleash your creativity and enhance your productivity.
LibreOffice is free. If you find it useful you can (and should) donate to the project.
Downloads can be found at: https://www.libreoffice.org

Logitech Capture
I use Logitech Capture for recording how-to videos for my team and also for keeping a record of activity during production incidents. Any time you want to have a record of what has been done it can be valuable.
Logitech Capture can be is a free tool and can be downloaded here: https://www.logitech.com/en-us/software/capture.html