Exact prices change frequently, which is why only approximate ranges are listed.
$ - Under $5
$$ - Between $6 and $50
$$$ - Between $51 and $250
$$$$ - Over $250
Constantinescu, A.I. (2007). Using technology to assist in vocabulary acquisition and reading comprehension. The Internet TESL Journal, 13(3). Retrieved from
Written by Tresa Jules, Last Revision April 2018