Apple's Family Sharing system has grown over the past few years from being a bit of a pain to one of the most robust options around.
Half of the problems I've seen stem from people setting up their child's tech with their own, adult, accounts. The minimum age for a regular Apple ID is 13, but you can (and should!) create one specifically for your child under your account, which can then be added to any device. You will essentially be an administrator of every device they use with this ID, enabling you to check screen-time, set content limits and so on.
Off the bat, everyone in an Apple family has access to all of the applications you've bought, along with your Apple Arcade, Apple News+ and Apple TV+ subscriptions. If you opt for an Apple Music family plan (which costs more than the individual one), you can share it, and if you pay for iCloud storage, ditto for that. Side note: A lot of people without children could and should be making use of Apple Family to save money on apps and services.
There are optional location-sharing (or tracking) features in the Family menu of iOS. Although I don't use these, my retired parents adorably share their location with each other (and by extension, me, as they are part of my Apple Family). It's integrated into the Find My app, and works well, but as my son is now in his teens I don't want to keep tabs on where he is at any given time.
What I do use on an almost-daily basis is Ask to Buy. This is on by default for users under 13, but it's very useful for teens as well. It sends a notification to your iPhone, iPad and Mac to let you know when your child would like to download an application, in-app purchase, song or video. (The App Store views getting a free app as a purchase, so the "Buy" in Ask to Buy is a slight misnomer.) From that notification, you can browse the relevant App Store page and see exactly what it is, how much it costs and whether it's suitable for your kid. Any adult in the family can authorize a purchase, but you can switch this off for certain adults (for example, I set up my family so my parents do not get notified when my son wants an app).
With Ask to Buy, you can decide on an individual basis which apps your child uses and discuss with them beforehand where necessary. You also never have to worry about a child spending money on in-app purchases and other things. While my card is connected to my son's account, he can spend no money without me explicitly agreeing each time.
More often than not, this adds five seconds to my son's app downloading process. However, I was able to sit down and chat with him about online safety before allowing him to install Instagram on his phone. And really, that's what Ask to Buy has done for me: allowed for supervision and conversations about how my son uses his phone, without needing to invade his privacy. While I could sit down and have these sort of discussions formally, that request to download an app like Snapchat or a game filled with microtransactions serves as a starting point to talk about these topics and makes resulting conversations more natural and relevant.
The benefits obviously extend to my child, as well. He has access to a vast library of apps and games I've already bought; he can make use of my subscriptions; and he effectively has a way to ask me to buy him something without needing to actually ask. That might sound mildly dystopian, but avoiding arguments by being able to click "decline" on a request and chat about why next time we're in the same room works for us. There are definitely times when the process frustrates my son -- especially if I'm in a meeting and slow to respond -- but he's aware of the net benefits of this arrangement.
Another important aspect of parental controls is the ability to see what apps your child is using and how long they're spending on their phone or tablet. Microsoft has surfaced this data for years, allowing parents to see what their kids are doing on Windows PCs and Xbox, but recently the concept moved into pretty much every OS as part of a digital wellness push to curb phone and tablet use in adults. As a result, tracked data is more robust than ever, and most people are now aware of how to parse it.
The only real negative is the restriction on family size
With Screen Time on iOS and Google's equivalent, you can be passive or active in your management. Passively, you can view daily and weekly reports on how and when your child is using their phone or tablet, and just keep tabs on things. If you need to, though, you can use the same tool to, say, stop phone use during classes at school or to lock a tablet an hour before bedtime.
The only real negative for Apple's and Google's setup is the restriction on family size. Both systems allow for you and five family members to share content, which covers every nuclear family I know, save one, but it really falls apart where, for example, two people cohabit and both have children from past relationships. While I understand the business practicalities of setting this limit, Apple should be more lenient with its cap on children while still limiting the number of adults sharing content.
If you already have an Apple ID, setting up a Family is simple. Apple has step-by-step guides for creating a child account and for creating a Family with existing child or adult accounts. Once a child hits 13, you'll be able to unlink their ID from your credit card, turn off Ask to Buy or remove them from the Apple Family entirely.
While not every Apple Family feature appears on Android phones (and vice versa), the broad strokes are there. Purchase and subscription sharing works similarly, the onerous family size limit is the same, and the Android versions of Ask to Buy and location tracking are in Family Link. One nice touch in Google's setup, especially for families with younger children, is an app guide that highlights teacher-recommended age-appropriate apps.
Both Apple and Google make it fairly trivial to manage which applications are on your child's device, then. But they understandably fall short when it comes to controlling what happens inside those apps.
One area many parents don't pay attention to is the internet itself: It's no good locking down every aspect of a phone then leaving a completely open browser sitting there on the homescreen. While you could block access to a browser entirely, most come with optional adult filtering and the ability to block specific sites. On Safari for iOS, for example, you can choose between allowing everything except websites you choose to block; using "limit adult sites" options to block common sites or blocking everything except websites you choose to whitelist. A similar safe-browsing mode is available in Chrome on Android.
Unfortunately, controlling what happens on services like Snapchat, Instagram, TikTok and Twitter is essentially impossible. For legal reasons, these platforms do not allow users under 13 to sign up, but even when your child becomes a teen, there is plenty of content out there that most would consider inappropriate for a 13-year-old. I know parents that actively prevent their children from using social media, but personally I am not comfortable with blocking access to services that serve as both primary communication methods and entertainment platforms for teens.
YouTube does have an app specifically for young kids, but although its filtering has improved, it still falls short in detecting inappropriate videos sometimes. For older kids, a restricted mode for the regular app and website similarly attempts to screen mature content and also prevents kids from seeing the comments. Setting this up on your child's device directly will have no real effect once they are old enough to realize they can just go into settings and toggle the switch. Instead you should use Google's previously mentioned Family Link system to apply that setting at an account level. I personally found restricted mode was a little too cautious, especially when it came to video game content, which makes up the bulk of my son's YouTube watching. I ended up disabling it a year or so ago and trying that whole "trust" thing instead.
There is no correct way to navigate the issue of social media and YouTube
One additional tip comes from a friend whose six-year-old worked out they could watch any video they wanted by just typing "youtube.com" into the tablet's browser instead of using the kid-friendly app: Use your device's aforementioned browser controls to blacklist the website.
There is no correct way to navigate the issue of social media and YouTube. If the thought of your kids running wild on YouTube is too much to bear, there are lots of apps specifically tailored for children, which provide a far safer viewing experience. We even produced a guide to navigating those options earlier this year. There will come a time when your kids will outgrow these services, though, and for my part, I try to speak with my son regularly about the dangers of interacting with people he doesn't know online, ask about what things he's watching and encourage him to think about the behavior of YouTubers like Pewdiepie and Jake Paul. But now we're getting into parenting, rather than parental controls, so let's move on.
The last app I'm going to talk about is Netflix, which is a big one, and honestly a bit of a mess when it comes to parental controls. Of course, setting up a kids profile is easy, and Netflix has settings that vaguely align to preschool, elementary school and high school. However, these profiles are less about blocking adult content and more about surfacing age-appropriate content. There are no locks on profiles, so there's nothing stopping a child from clicking on your profile when they open the Netflix app on their device and gaining access to every horror movie on the service. If you want to prevent that, you need to restrict content behind a PIN.
You can set up a Netflix PIN to restrict access based on a show or movie's age certification or pick specific shows to lock. The annoying thing here is that, due to Netflix's lackadaisical profile security, this PIN then applies to all accounts, meaning you as an adult will constantly be typing in your PIN every time you want to watch something. The more sensible approach would be to allow adults to lock their profiles behind PINs, but Netflix does not do this.
Netflix is the perfect example of the imperfect world of parental oversight. You're never going to control everything your kids see and do, and children will find holes in systems without even trying. All you can do is be aware of what's available to you within an OS or app and create a setup that works for you.