Free Chinese dictionary apps: iCED

12/22/11:  The ABC Edition is $14.99 until 1/3/12 (50% off).  I believe it should be the same as the free edition after you have bought the Add-on of the ABC Chinese-English dictionary, which I have, and am happy using.

Parent blog entry: http://kenamored.blogspot.com/2011/03/free-chinese-dictionary-apps.html

My preferred Chinese dictionary app. Its usage of the visual tone choices (see below) can save time when looking up a character phonetically, and is more smooth all around. It is also the only dictionary app I know of which allows you to copy out (to other apps) Pinyin syllables with tone indicators just like you would write by hand, e.g., Hǎo bàng! （好棒，Excellent!), instead of having to write Hao3 bang4!
PROS:

• Adds all 5 visual tone choices as separate buttons to tap above the English keyboard, e.g., a horizontal line for first tone, as people would normally write by hand.  I'm used to adding numbers to indicate the tones, but this functionality saves you from switching to the number keys when entering Pinyin.
  
  
• You can copy and paste Pinyin syllables having these visual tone choices.

CONS:

• Ads. This app serves me so well that I paid to remove the ads. I don't have an iPhone, so never really thought about how such ads nibble into one's 3G data usage, but that makes sense.

CC-CEDICT DICTIONARY LINGUISTIC ISSUES (which are not iCED's responsibility):

• 10/16/11: The surname whose Pinyin is Oū is given as 區, and for practical* reasons should perhaps be given only as 歐. Pleco, for instance, has it as 歐, which matches what my native Chinese speaker source expected.
  Neither the 844-page Far East Pinyin Chinese-English Dictionary, published in 2008, nor the 1762-page Far East Chinese-English Dictionary, published in 1992, include 區 with the pronunciation Oū; in traditional Chinese, 區 is always pronounced qū, and is not a surname.
  The 976-page simplified Chinese The Pinyin Chinese English Dictionary, published in 1991 by The Commercial Press, gives both 区 and 欧 (the simplified Chinese versions) as an Oū surname, but I suspect that 欧 is far more common than 区.
  
  * It is not possible to wholly map traditional Chinese and simplified Chinese on a one-to-one character basis, although many apps, like iCED, make some attempt to do so, to serve users of either.