Where did I stay ?: According to information from Amazon, the Whispersync function allows you to synchronize and save the last page you read and you can visually mark points in the reading in a discreet way. If you have the Kindle app on several devices, the system will allow you to see the bookmarks on them.
More information: There are two functions that can help when you need more explanations about some phrases or words. One of them is Word Wise, this can be configured from the menu and allows that when selecting a word meanings are shown. Another way to do this is to integrate dictionaries into your configuration so that the reader can display explanations from Wikipedia, when you select a word.
X-rays: Just as there is an additional information bar on the left side of your screen when you watch a series or movie on Amazon Prime, on Kindle you can activate this function and see more information and data on the characters, their historical significance or famous passages from the work.
Alexa, read for me! In case you prefer that the virtual assistant read for you it is possible.
Some of the books included in Kindle Unlimited, which comprises around 1 million titles, are compatible so that Alexa can read them. This format has a cost of 129 pesos per month.