
The new Mac operating system holds many secrets. Here are all the tips you need to know to master it.
macOS Catalina (10.15) is officially available. Downloadable for free from the Mac App Store, Apple’s new operating system is compatible with machines dating from 2012 and newer.
On its dedicated page, Apple specifies that you must also have at least 4 GB of RAM and 12.5 GB of storage space (or 18.5 GB of space if you are updating from Yosemite or earlier) to install the macOS Catalina update.
The arrival of this new version of macOS also signals the death of 32-bit applications. Before embarking on updating your Mac, be sure to check that all the applications you use on a daily basis and which you cannot do without are 64-bit.
If you’ve taken the plunge and installed macOS Catalina on your machine, the following lines will give you tips on how to master Catalina like the back of your hand.
1. Use the automatic dark mode display according to the time of day
The ability to use a dark theme on Macs isn’t new. This feature was integrated last year in macOS Mojave. However, it had its limits, since it was only possible to use either the light theme or the dark theme.
macOS Catalina is a game-changer and now offers the possibility of taking advantage of both themes, with an automatic activation of the dark theme, depending on the time of day, and therefore the ambient light.
To take advantage of it, open System Preferences then in General, switch Appearance Mode to Automatic.

2. Use an iPad as a second screen
macOS Catalina introduces Sidecar, a feature that lets you use an iPad as a secondary display for the Mac. To work, Sidecar requires an iPad updated to iPadOS. The rest is very simple, since it is enough from the System Preferences, to go to the section dedicated to Sidecar, and to select the device to connect to.
You can then choose whether or not to display the sidebar and the Touch bar, as well as define their position on the iPad.

3. Find your lost devices with Find My
The Apple device tracking feature is directly associated with the configured iCloud ID. To make sure it is properly enabled on your Mac, open System Preferences and click Apple ID.
Scroll through the list of apps on this Mac using iCloud, and enter Find My Options. If you haven’t already, you should be able to turn on Find My Mac as well as the Offline Search feature.

This allows you to locate your devices even when they are not connected to the Internet. Concretely, your Mac, even offline, will attempt to detect nearby Apple devices by sending them a Bluetooth signal. These will then relay the position of the lost machine to iCloud to allow you to locate your machine.
Then open the Find My app on your Mac. This new version of the app includes the location of all your devices connected to the same iCloud account, as well as the location of your friends.

4. Watch any video in Picture in Picture
Safari, Apple’s web browser, but also QuickTime Player, are now able to display all the videos played in Picture in Picture mode.
On Safari, while playing a video, right click on the sound icon displayed on the tab, and choose to Enable Picture in Picture mode.

In QuickTime Player, while playing a video, bring up the control buttons, and simply click on the icon on the far right.
5. Use Screen Time
Since iOS 12, iPhones and iPads have taken advantage of Screen Time, an app that allows you to manage the time you spend in front of the various programs installed on your devices. The function makes its appearance on Macs thanks to Catalina.
You will find it directly within System Preferences, where a Screen Time section is present. Thanks to it, you can monitor the time spent on the various apps installed on the Mac, know the number of notifications received, or even find out the number of times you have used an application.

Screen Time also allows you to configure certain limits. For example, you can define a time slot during which you will not use a screen, and you can configure usage time limits for certain applications.
It is also from Screen Time that it is possible to set certain restrictions to prevent access to certain explicit content, prohibit the purchase of applications and content, etc.
6. Sign a document using your iPhone or iPad
If the Preview application already allowed you to put a handwritten signature on documents by signing using the trackpad of the Mac or by photographing your autograph made on white paper using the webcam of the Mac. With macOS Catalina, you can now use an iPhone running iOS 13 or an iPad running iPadOS to create your signature, handy for those who use a Mac without a trackpad.
Open a document in Preview, display the annotation toolbar, click the Signature icon to Create a signature.

Logically, if your iPhone or iPad is nearby, an iPhone or iPad tab should be present. Then select the device you want to use to create your signature to bring up the signature interface on the iPhone or iPad. You can use your finger to sign, or an Apple Pencil if you have one.
7. Back up your iPhone directly in Finder
With the dismantling of iTunes, management of iOS and iPad devices is now done directly from the Finder. Connect your iPhone or iPad to your Mac in Catalina to “mount” it like any other device in Finder. Then just click on the device to make the data sync window almost as it was in iTunes.

8. Unsubscribe from newsletters and mute boring conversations
The macOS Mail client now makes it easy to unsubscribe from newsletters that invade your inbox, as is already possible on iOS. Click Unsubscribe on the right, just above the message.

In addition, Mail now offers a tool to silence the whistle of certain conversations. Select the conversation you want to silence, then, in the Mail toolbar, click the crossed-out bell icon.

9. Validate the passwords on your Mac with your Apple Watch
Apple Watch owners could already unlock their Mac using their watch. With Catalina, they can now automatically fill in passwords to log in online or complete certain authentication procedures, without having to type anything.
To take advantage of these new features, you must have an Apple Watch under WatchOS 6 and above and activate the unlocking of the Mac with the Apple Watch. Open System Preferences, enter Security & Privacy options, and check Allow your Apple Watch to unlock your Mac.

Therefore, when you will be asked to enter a password on your Mac (in Safari, for example), all you have to do is validate your connection by pressing twice the side button of the Watch to validate your authentication.
10. Effectively manage the display of windows
Arranging windows in Catalina just got easier. Hover over the green button to maximize the window to display the available options. You can choose to display the window in full screen, but also place it on either side of the screen.

If you opt for the latter possibility, a click on a second application will suffice to display the two, side by side, in Split View.