Myo Mapper is a free and open source cross-platform application to map data from the gestural device Myo armband into Open Sound Control (OSC) messages. It represents a `quick and easy' solution for exploring the Myo's potential for realising new interfaces for musical expression. Together with details of the software, this paper reports some applications in which Myo Mapper has been successfully used and a qualitative evaluation. We then proposed guidelines for using Myo data in interactive artworks based on insight gained from the works described and the evaluation. Findings show that Myo Mapper empowers artists and non-skilled developers to easily take advantage of Myo data high-level features for realising interactive artistic works. It also facilitates the recognition of poses and gestures beyond those included with the product by using third-party interactive machine learning software.