If you are using Hue dimmer switches as a parallel means of control or a HomeKit accessory, there’s now a really nice $10 adapter with magnets that just sits on top of the existing rocker switch. Then you put the dimmer switch on top of that. No more child locks! 
There have been similar plate covers available in the UK for a while, and some that were 3-D printed and available individually through Etsy, but this is the first mass-market one I’ve seen for the US. It’s also available to fit over toggle switches. 