I've been using Comixology on various devices since before Amazon acquired them. They had finally worked out most of the issues only to merge with Kindle. Comixology was specifically designed with reading comics in mind, whereas Kindle is designed for books. This is a major step backwards. I've had to re-download comics, and my saved reading progress is dubious at best. Additionally elements such as guided view where it zooms in on a single frame are broken. Very disappointed.