Amazon released a big update to the iOS kindle apps (iphone, ipod touch and ipad) yesterday. This brings it in line with the Kindle Fire apps.
The main new feature is the ability to listen to the audiobook directly in the kindle app. Previously you could sync your location in the kindle app and the Audible.com app, but you had to alternate between the two apps. Now you can do “˜immersion reading’ and listen to the audiobook while seeing the words.
For most people, it is just a good feature to keep your place while alternating, but Amazon markets the feature to help kids learn to read.
I do like the syncing feature (although it requires you own a copy of both the audiobook and the kindle edition). I briefly tried it out the iOS kindle app last night and this morning and it seems to work well.
Any book that you own both versions (there is often a discount if you purchase the kindle edition first) has a headphone symbol in your library.
If you want to try the feature out without spending much money, there is a list of $0.99 classics, where the kindle edition is free and the audiobook is only $0.99.