I have a new app out. It is "Grandmaster of Memory". Although it's not finished, you can use it to test your associations of playing cards to images and numbers to images. More functions will be added. You can download it on the app page in the description on the right. Thank you!
Avatar: The Last Airbender Question: I wanted to post this on TV tropes, but I don't want to get an account. Instead of surrendering when the fire nation launches a counter-strike on their submarines, why don't earth-benders try to tunnel their way off the island? In fact, in preparation for the invasion, why don't Toph and other earth-benders create a tunnel system under the island to use to raid or to create a giant sinkhole during the eclipse?