Here’s one more reason to love technology: it makes it so much easier to keep the kids quiet during Memorial Day car trips. Just toss a tablet or smartphone stuffed with apps onto the back seat. But which apps? Luckily, there are plenty of good ones. Some, like Apple Inc.’s iMovie, are mainstream apps that are ideal creative tools. Others, like Children TV and Famigo Sandbox, are clever little programs that lock out inappropriate content to instantly child-proof your phone.