I just purchased a couple of 2014 fire hd's for my 4 yr old twins. I installed a really good children's app launcher, but it wouldn't lockdown. I thought blocking the com.amazon.kindle.otter would make it work better by only using the kids app launcher. Problem is I forgot to reinstall the kids app launcher before reboot. Now, I can't get past the fire logo and I can't reboot or erase, etc. through adb because I can't sign the confirmation on the device. I even tried installing an app launcher through the file explorer internal storage folder on my pc. Any ideas? Christmas is fast approaching:O.