If you don’t know this app already and if you DO know a child, go get this immediately. It teaches letter names, letter sounds, spelling and vocabulary words with the most charming and hilarious monster illustrations and animations. I especially love that the vocabulary words they choose to include aren’t always everyday words, but are often "rare" words like quarrel, demolish, gargantuan and famished. Because the app is so easy and attractive to use, my own kid plays it over and over and I’ve even heard him working those new words into his own vocabulary! (NOTE: the Android version is free with in-app purchases, iOS version is paid.)