Phaidon Design Classics is a book (or really, a three volume set) for design nerds like me. In it they curate and chronicle 999 objects that they deem are noteworthy for their innovation, influence and are "perfect in their design." The objects are numbered and ordered chronologically, starting with Chinese household scissors from 1663 and ending with the most modern products of today.
Though you could buy the three volume set at Amazon for $110.25, for $19.99 you can get all of that content and more on your iPad - plus an extra product (product 1,000 - the suitably chosen iPhone). It's an awesome collection of things both historical and current, allowing you to browse through not only the history of object design but human history as well.
The interface is fairly easy to understand, and while the clicking sounds it makes when you transition to a new object are kind of hokey, they do help you navigate through the enormous collection. You can also narrow down the number of objects shown by choosing categories or by running keyword searches on the titles and descriptions.
Running a search on "children" yields 49 results, among which there are some of the things you might expect, like the Mammut Chid Chair sold by Ikea, the Tripp Trapp Child's Chair from Stokke or the Eames Hang-It-All. There are also many objects that are taken for granted but are nevertheless incredibly innovative, like Crayola Crayons, Pez candy dispensers, the very first Jigsaw Puzzle (made in 1776), or the very first Teddy Bear (made in 1902). I must admit that I never really gave much thought to the Classic Red Wagon from Radio Flyer (pictured), but two paragraphs later not only do I know the history behind how it was designed and developed, but I appreciate it all the more.
Phaidon Design Classics for iPad by Phaidon Press, $19.99 from the iTunes App Store.