So, this page is not strictly Ubuntu specific. Here I will add Kindle related info that I consider useful and want to save.
- The kindle may become slow, especially when using collections. One reason is that some books are not correctly indexed. These should be removed. To find them, go To Home and type xxxyyyzz. This gives access to Items not yet indexed. Take down these books and then use Calibre to find, save to disk and remove them from kindle. Trying that again may show even more books not yet indexed. If they are too many, consider removing them too, because the most important reason for the kindle being slow is the unreasonable number of books. Kindle states to be able to handle up to 3500 books. But that means that after that it will be dead: before that it will be ill. So, just use only hundred of books, or better use as less as possible. Backup them and delete them from the Kindle. The best way to do it is Calibre, because it can give easy access, search capacity, selection and manipulation. Just look in the device, be sure you have them all in the Calibre library (which means they are saved on the computer (home/username/"Calibre Library"). You can save all to disk again if you want, and then delete most of them, except some that you hope to read soon.