Kindle App crashing on iPad

If it only happens using that app, and if you're sure that your Kindle app is updated, try a forced restart of your iPad: put it on charge for at least half an hour, then, keeping it plugged in, use these instructions:

• On an iPad with a Home button: Press and hold the top (power) button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On other iPad models: In rapid sequence, press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top (power) button. Only when the Apple logo appears (it might take 10-20 seconds), release that button (ignore all other screens that might appear, the one with the "slider" to turn the device off included).

If the issue still persists, I suggest that you contact Kindle developer/support team and ask them:--> How to contact an app developer - Apple Support

Regards

Giulio