yes, the problem is known and it is by far our top crasher. It ONLY happens on Amazon Fire devices but not on the (old) one we have on our disposal...
Currently I do not know how to fix it.
If you have time, you may help us finding the problem. Can you please try the following versions and tell us, which do work and which crashes when adding the image. Please note that installing these versions will most likely wipe out your current configuration and profiles, so make sure you store the current profile and store the $SDCARD/Android/data/de.appnotize.letmetalk/files/backup folder somewhere else, best on another device.
Here the list of versions. Please give them all a try and tell us which version works and which crashes. This will help us to find the problem