If you use a Fire Tablet and you want prevent kids from ads do:
- Enable the Developer Options by Settings > Device Options > Tap on Serial Number several times > You are now Developer
- Enable the USB Debugging on Setttings > Device Options > Developer Options > Enable ADB > Tap on toggle > Enable
- Connect the Tablet to a Linux PC with installed „android-tools-adb“ on Win use Adb-Tools-Package from Google
- Open a Terminal enter
Fire OS 5.0.x:
adb shell pm hide com.amazon.kindle.kso exit adb reboot
Fire OS 5.1.x+
adb shell pm clear com.amazon.kindle.kso pm hide com.amazon.kindle.kso exit adb reboot
After reboot test the Tablet, the ads should be gone..
Remark: if you remove the Account you don’t need this workaround, and if the account is removed and you try to login later the ads are displayed again. The Tablet is yours!
Update: Since Firmware update to 5.3.X the Amaz Developers seems to run a cronjob which enable the Ads again after some time! Try to block from calling home the Tablet via your Home Router Outgoing Firewall! Or if you use a DNS Server set the amazon update domains to 127.0.0.1 at the DNS Server Hosts File. Then the Tablet isnt able to pull commands and force ota Updates!
Block this Domains (or disable all Internet on the Kids-Rules of Firewalls):
amzdigital-a.akamaihd.net amzdigitaldownloads.edgesuite.net softwareupdates.amazon.com updates.amazon.com 126.96.36.199/8 188.8.131.52/8