KeePassXC is an open source, cross-platform, password manager coming as one of the forks of the KeePass project.
While my main password manager is 1Password, I am using this for the safes used at work, hosted on our own cloud storage system.

While using Apple Silicon machines allows me to use some alternatives (like Strongbox or KeePassium), on the Intel architecture I am ok using this software.

Here's the mounted DMG volume as of 27 april 2024 (but I've verified this has not changed in the latest 2.7.9 release in 2025).

The DMG icon, instead is a generic one, with no customization.

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Source: https://keepassxc.org/

Telegram is an instant messaging app I've been using for quite long time now. I use it mostly with my geek contacts and to follow some informative bots. I can safely say that I've never used it for any kind of communication with my family (in its most wide meaning).

Those are its icons and mounted DMG volume on my desktop as 4 November 2024.

Source: https://telegram.org/

Little Snitch is my premium (as paid) software for macOS firewalling. I have been a customer since release v3, now years later we've just reached the 6th version.

Here's a small review on the AppAddict.

Those are its icons, as of 3 December 2024.

This is the mounted DMG of the app on the 11 december 2020.

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source: https://obdev.at/products/littlesnitch/index.html 

FreeTube is a YouTube client for Windows, MacOS and GNU/Linux built around using YouTube more privately.
Here's a small review in the AppAddict pages.

Those are its icons as of 21 November 2024.

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source: https://freetubeapp.io

Onyx probably is the first app I install on any new Mac computer I own. I have also to admit that I upgrade my operating systems when the appropriate release of Onyx is published. This says all - I think – on how much I like and trust this ‘small’ utility for macOS.

Here's a small review on AppAddict.

Those are its icons ad of 12 November 2024 for the macOS Sequoia release.

These are the icons for the macOS Sonoma release, as of 12 october 2024.

These are the icons for the macOS Monterey 12 release, as of 2 november 2021.

This is the DMG icon of the macOS Big Sur 11 release as of 9 march 2021  

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source: https://titanium-software.fr/en/onyx.html

Adium is a free instant messaging application for macOS that can connect to XMPP (Jabber), IRC and more. Those are its icons ad of 12 November 2024.

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source: https://adium.im/

Lulu is an open-source macOS firewall application. As far as I can remember this app has never changed its look.

Here's a small review on the AppAddict.

Those are its icons, as of 28 October 2023.

On November 12th 2024 the artwork is still the same. --
source: https://objective-see.org/products/lulu.html

Arc icons as of 29 august 2023

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source: https://arc.net/

Discord art, as of 3 august 2023

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source: https://discord.com/

Skype icons as of 26 July 2023

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source: https://www.skype.com/