Flowers are not unique - there are many that are infuriatingly similar. A big bonus of software over books is easy comparison. 

This example is of yellow Dandelion-like flowers. In the left-hand window are thumbnails and identification tips, while in the right-hand window you can bring up larger images of the flowers, and, from these, link to the flower details.

There are also comparison pages for Buttercup-like flowers, red Cranesbills, red Thistles and similar flowers, Speedwells, Campions, white Daisy-like flowers, Orchids, and White Umbellifers and similar flowers,.

NOTE: The picture on the right is only an illustration - the buttons don't work!