This is my 2024 roundup of macOS tools. I was using all of them at the time, and among their peers I found them the handiest. Below is that personal selection, organized by purpose. Features and pricing are subject to the current official descriptions; this isn't a promise that I still use every one of these apps today.
The images are app icons, not screenshots of the latest versions. Free, trial, and paid are distinguished based on the official descriptions I checked this time; actual purchases depend on the current version, channel, and plan.
Essential Tools

Raycast: app icon (not a screenshot of the latest version)
Raycast · Core features free, paid plans available · Website
Hit a keyboard shortcut to open the launcher, search for apps, files, or commands, and connect to other tools through extensions. The extension repository offers plenty of optional plugins you can configure to your liking. The launcher's free core features are separate from paid services like Pro and AI, so you can't just say all of Raycast is free.

Mos: app icon (not a screenshot of the latest version)
Mos · Free, open source · Project
Mainly for smoothing out mouse scrolling and adjusting direction. You can tune horizontal and vertical scroll direction, speed, and acceleration to your habits, and control scrolling behavior with shortcuts. What it improves is wheel input, not a replacement for every trackpad gesture.

SoundSource: app icon (not a screenshot of the latest version)
SoundSource · Paid, with a trial · Website
Manage input and output devices, system volume, and per-app volume from the menu bar. If one app is too loud, you can turn it down on its own, or route an app to a specific output device and apply audio effects like an equalizer. Before installing, check the current macOS and hardware support; don't read "supports Mac" as "supports every OS version."

Aibo NTFS Assistant: app icon (not a screenshot of the latest version)
Aibo NTFS Assistant · Paid, with a trial · Website
macOS can usually read NTFS drives but doesn't offer full write access by default. This kind of driver fills in NTFS read/write so you can exchange files on hard drives or USB sticks with Windows. The current OS version, chip architecture, and drive state all need to be checked separately; there's no guarantee it works unconditionally on any version or any drive.

Keka: app icon (not a screenshot of the latest version)
Keka · Free download from the official site, paid support channel on the App Store · Website
Drag and drop files to compress or extract, with options for compression level, encryption, and splitting. It can create ZIP, 7z, and more, and it can extract RAR, but don't mistake "supports RAR" for being able to create RAR files. Supported compression and extraction formats need to be looked at separately.

CleanShot X: app icon (not a screenshot of the latest version)
CleanShot X · Paid · Website
Full-screen, area, and scrolling screenshots, plus screen recording, annotations, and cloud sharing all in one tool, with custom shortcuts. Cloud storage, links, and update entitlements vary by plan; not every feature is included without limits. The trial marker in the old list isn't a guarantee that a free trial exists now.
System Enhancements

AutoCode: app icon (not a screenshot of the latest version)
AutoCode · Currently listed as free on the store page · App Store
For handling SMS verification codes across devices. It doesn't work with every authentication method; email verification links, third-party authenticators, and SMS codes aren't all the same thing. Check the current app description for supported sources, system requirements, and permissions, and it's worth looking at the privacy permissions of any verification-code tool first.

Bartender: app icon (not a screenshot of the latest version)
Bartender · Paid, with a trial · Website
Organize menu bar icons, hide the ones you don't use often, reorder them, and bring them back with a shortcut. What it manages is menu bar items, not macOS Notification Center, so don't treat it as a priority manager for system notifications.

AltTab: app icon (not a screenshot of the latest version)
AltTab · Free, open source · Website
Brings Windows-style Alt-Tab window switching to the Mac, with thumbnail previews so you can jump straight to the window you want. Shortcuts, filtering scope, and switching behavior are all adjustable, which suits a workflow with lots of open windows.

Maccy: app icon (not a screenshot of the latest version)
Maccy · Open source, pricing varies by download channel · Website
Keeps a clipboard history, lets you search things you've copied before, and pastes them quickly. You can adjust history size, shortcuts, and what gets ignored. Passwords, tokens, and sensitive text shouldn't sit in clipboard history long-term, so configure exclusions or clear it regularly; also don't lump the website version and the App Store channel into one price conclusion.

PopClip: app icon (not a screenshot of the latest version)
PopClip · Paid, with a trial · Website
Pops up an action bar when you select text, so you can copy, search, translate, or run other actions through extensions. The trigger is selecting text, not "appearing after you copy." The old list marked it as free; this is a correction.

AppCleaner: app icon (not a screenshot of the latest version)
AppCleaner · Free · Website
Drag an app in, review the associated files it finds, then decide what to delete. The preview list matters more than deleting blindly; it can't guarantee it finds every leftover, and you shouldn't treat the deletion preview as a separate backup. Important files still need their own backup.

Tiles: app icon (not a screenshot of the latest version)
Tiles · Free · Website
Drag windows or use shortcuts to snap them into preset positions and sizes. It solves quick window arrangement, not saving and restoring the state of every app; whether you need an extra tool depends on your own window habits.

Stats: app icon (not a screenshot of the latest version)
Stats · Free, open source · Project
See CPU, memory, disk, and network metrics in the menu bar, plus hardware data like temperature and fan speed. Which sensors it can read depends on the model, system, and permissions. These metrics are for observing load; having it installed doesn't mean it automatically optimizes performance or diagnoses every hardware problem.
Browsing & Entertainment

Chrome: app icon (not a screenshot of the latest version)
Chrome · Free · Website
A cross-platform browser with extensions, themes, bookmarks, and safe browsing. Once you sign in and enable the relevant sync settings, you can sync selected data across devices. Extensions have their own permission and security boundaries too, so don't ignore what pages they can read just because they come from an extension store.

IINA: app icon (not a screenshot of the latest version)
IINA · Free, open source · Website
A macOS video player that supports many common media formats, subtitles, picture-in-picture, and playback parameter adjustments, and can handle some streaming inputs. Whether playback is smooth still depends on the file's codec, hardware, and decoding conditions; no promise that every large file will play smoothly.

Downie 4: app icon (not a screenshot of the latest version)
Downie 4 · Paid, with a trial · Website
Saves media from supported video sites, with batch tasks and related output options. Site support changes over time, and download capability doesn't equal permission to repost or distribute; only handle content you have the right to save.

Permute 3: app icon (not a screenshot of the latest version)
Permute 3 · Paid, with a trial · Website
For media format conversion and batch processing, with simple operations like trimming, rotating, and resizing. Check the current version for specific input and output formats, and don't treat it as a full video editing suite.

HandBrake: app icon (not a screenshot of the latest version)
HandBrake · Free, open source · Website
For video transcoding, compression, and parameter tuning, with presets and manual control over encoder, quality, and other options. Output containers are MP4, MKV, and WebM; don't count AVI as an output format. Being able to read an input and being able to produce an output are two different things.
Reading & Writing

Typora: app icon (not a screenshot of the latest version)
Typora · Paid, with a trial · Website
A Markdown editor that shows formatting as you write, with support for headings, lists, code, tables, and themes. There are versions for macOS, Windows, and Linux; syncing across devices is handled by whatever sync service the files live in, so installing Typora doesn't automatically sync your documents.

UPDF: app icon (not a screenshot of the latest version)
UPDF · Paid, with a limited trial · Website
For PDF editing, annotation, page management, conversion, and protection; OCR, AI, and other capabilities and usage quotas need to be checked separately by version and license. Don't assume the base purchase includes every add-on service.

Tuya: app icon (not a screenshot of the latest version)
Tuya · A historical tool kept from the original list · Original project site
In the original list, it was a free local image compression app, including compression to a target file size, useful when you hit upload limits. I couldn't access the original project site this time, so I haven't confirmed its current maintenance status, download availability, or system compatibility; don't take the historical description as a guarantee that the service still works today.
After compressing, still check the image and text; no promise that every image can shrink dramatically with zero visual loss.