DecoChek Desktop is written in Java, and should run an any machine with a Java Runtime Environment of 1.4 or higher. If you haven't already got Java on your machine, the latest version can be downloaded here. For the convenience of Windows users, a single DecoChek Install file is available.
DecoChek Mini runs on any phone with CLDC 1.1 , which should mean most phones manufactured after 2005. Depending upon your phone type, you may have to download either or both of the two files below. Try downloading the .jad to your phone first, which should then automatically download and install the .jar file, complete with icon etc.