As a engineer this (Airconsole) is one of the best and most used tools in my toolbox! All my customers me ask about it
Whether you have the serial adaptor or are just looking for a telnet/SSH client its the only one I have found that satisfactorily supports an external keyboard. Has good frills and no-frills mode. Highly recommend.
The latest update to the iOS SDK adds further Serial over Bluetooth Low Energy functionality.
4 Port Serial Cable released for Original Airconsole 1 and Airconsole 2