A few online resources that have word unscramblers are Your Dictionary, Anagrams Solved and All Scrabble Words. These unscramblers can decipher jumbled words of different lengths. For example, the All Scrabble Words site can unscramble words with up to 12 letters for different languages, including English, French and Italian.
The All Scrabble Words site also has lists of words of different lengths that are often scrambled and words with popular letters to unscramble, such as x, y and z. There are also lists of unscrambled words that have different endings, including -en, -ness and -ment.
At the Your Dictionary site, the scrambled letters are typed in the provided space, and this generates a search through the dictionary that gives a listing of words. For example, typing in the letters "arbeeth" generates a list of 105 words, including breathe, bather, breath, heart, bath and bat.
The Anagrams Solved resource has a Scrabble helper that can unscramble words up to 16 letters. The unscrambler has features such as returning results that have a certain prefix or postfix. For example, typing in the jumbled letters "theare" and restricting the results to have the prefix re-, generates a list of words only starting with this prefix, such as reheat.