This is a very handy feature for all Kindle users. But, it is especially useful for people like me who often want to prop up a technical book/manual next to a PC for reference. Although I can already do this using, for example, GoodReader or iBooks on an iPad, doing so eats up the device’s battery and shuts off the display after some fixed period of inactivity. The e-ink Kindle, however, does not suffer from either problem when a page is left up on its display. The free app for Windows PC was announced on the Kindle Daily Post blog.