Download of LetterMess 1.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free software for Mac is Meilenstein Software GmbH. The software relates to Education Tools. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
According to research at an English university, it doesn't matter in what order the letters in a word are, only that the first and last letters are at the right places.
The rest can be a total mess and you can still read it without a problem. This is because we do not read every letter by itself, but the word as a whole.
You may want to check out more Mac applications, such as English-Italian Dictionary '08, Japanese-English Dictionary or NounStar Language Study - Desktop Edition, which might be related to LetterMess.