For the life of me, I cannot find any good child lock app for my Android phone. Let's take a look at the options. Perhaps we can find a reasonable compromise. If you are thinking that your child lock is great, you should take a closer look.
First I tried Zoodles Kid Mode, which appears to be designed for this purpose. The problem is that like many other such platforms for kids, Kid Mode forces some content onto my child. I don't get the point of this practice. Child locks are intended to allow the parent to decide what content should be accessible to one's child. So why does Kid Mode insist on providing TV access to my son? It cannot be disabled along with several other features that I find inappropriate. Chances are Zoodles gets some kick backs from the content providers. It's essentially adware for children.
The next try is Kids Place. This one is better in that it allows me to choose exactly the games I want my son to play with. It locks the phone pretty well. It cannot be escaped as far as I know. Long-pressing the home button opens the app switching window, but tapping any of the running apps brings up Kids Place blocking message rather than the selected app. So far so good. One thing you will notice pretty soon is that the app regularly begs for recommendation on exit, which is annoying but bearable. Much worse problem is that Kids Place slows down the main Android launcher app, i.e. the home screen. Screen Lock Widget, which I use to save wear on the power button, takes several seconds to lock the phone when Kids Place is installed.
This slowing down of the phone is typical for all the child locks. The problem is that child locks operate as an alternative launcher in the Android system. They plug themselves in when started and then unplug when they are closed. Apparently this causes some conflicts with the main launcher, which is then slowed down massively.
One option I have been thinking about is just using launcher that would allow me to setup two separate home screens, one for my regular use of the phone and one for gaming. While looking for options to speed things up, I came across Lightning Launcher Home, which is pretty fast and highly customizable and there is a paid upgrade Lightning Launcher eXtreme, which promises multiple desktops, but there is nowhere any mention of making those desktops locked, i.e. safe for kids. There's a support community for Lightning Launcher and I have posted a question there. Judging by the responses Lightning Launcher is unable to provide child lock functionality. There are some customizations that approximate it, but they are still too easy to escape by a child randomly tapping around.
So are there any Android launchers with integrated child lock? There are some launchers like Kid's Shell that seem to be intended as a primary launcher on the device, but their parent mode, i.e. the desktop that I would use, is severely limited. These launchers are better suited for tablets and phones used exclusively by children. I will consider this option when my son gets his own tablet.
There's Personal Launcher that is more adult-oriented, but it is unfortunately marked as incompatible with my phone. I wonder what's the point of a launcher with user profiles that requires high-end Android device. Those devices have built-in user account functionality since Android version 4. Anyway Personal Launcher looks interesting. It is not a complete child lock though. For starters, it doesn't hide the notification bar (according to comments on its Google Play page), which allows easy access to various system-level apps.
As far as I understand it, child lock is more than a locked down desktop without notification area. Child locks also pull other tricks like dropping incoming calls, blocking task switching via long-pressed home button, or blocking all wireless transmissions. This means that a launcher with integrated child lock is going to require extra permissions and it will perform some invasive changes in the system. This may cause some of the problems I experience to return. It would be worth a try though.
For newer devices, Android 4 provides multiple user profiles. I am not sure how far this function goes. I guess it just prevents users from accessing each other's data. I will nevertheless review this option when buying a new tablet, which is likely to be used by multiple people in contrast to phones, which are much more personal devices.