Mac Users

If you are using a Mac, to run the server, (for the moment) you need to use the command line (terminal):
(Once you are in the folder containing the server .jar enter)
java -jar filename.jar

It's a pain in the a** but, if you try to double-click the .jar file, you will just get errors. 

Also, to use the app with a Mac, you need to enable the IAC Driver. This can be done from:
Applications > Utilities > Audio MIDI Setup and make sure the device online checkbox is ticked.

From there, it should show up in the list of compatible devices generated by the server. IAC routes the MIDI from the server to your apps, so make sure IAC is selected as your DAW's MIDI IN port.

Server for BluPad v1.18

BluPad is now on the Android Market!
The server for the current version of the BluPad app is available here.
The server is designed for use with Win XP/Vista/7 only. It will work with Mac but you will need to find a suitable loopback driver to forward the MIDI from the server to your DAW use Apple's IAC driver.

V17 - APK & Server

Latest version of the app and server is available here.
Just use the v1.18 market/server link above, it's easier that way.
You can still give feedback on the app here.