You can check out the site here:

http://www.theoreticallycorrect.com/transposer/index.html

It basically promises a very fast and accurate transposition of chord in songs that we can find online. It looks a bit like a text editor that will recognise the chords, just check out the quick demo video on the site and you’ll see what I mean.

It is quite a handy way for songwriters, beginner guitarists or singers that want to find a way to play their favourite song in a more comfortable key.

In a way it is what the site chordie has online, in a portable format, in case you had no connection.

These are great tools, but in my opinion not to be used without knowing the theory behind transposing music, a necessary skill if you are serious about making music.