The main competitor to sites like this is GoAnimate, a website where everything costs money.
This website is much safer when it comes to consumerism. Three months of GoPlus was* $18 while six months of VIP here is $19.95. GoAnimate is also strictly against using for free. They're eliminating free plans, but this site lets you use a demo (no free trial) of what it's like minus VIP features before you buy.
Children can share their videos with other kids using the site (unlike Don'tGoAnimate) and can forever do that. Some videos become Crowd Pleasers, or the site editors can even deem it 5/5 material and it becomes a Must-See.
As for VIP, a month costs $4.95 and six months give you a discount and, as mentioned earlier, cost $19.95.
This is a safe option for you and your kids.