***** This is one of my most frequently used, and most highly recommended study tools *****
Unlike the Strong's concordance, which does an english word search in the KJV, this Greek concordance does a word search in the original language on any particular greek word you want.
The Strong's could search "love" which would give you a list of all types of love, possibly missing
some "agape's" if they were rendered "charity" or something else. The Englishman's would give you every single "agape", not matter what english word it was translated as, and it would put the translated word in italics, so you can scan down the page and see different ways it was translated throughout the NT.