The configuration
The strength of Push Push is the ease of configuration: you don't need to modify the Arduino code or use complex software to configure the key sequences to send: just use the Push Push Editor.
The communication between Push Push and the editor is based on the MIDI protocol, exchanging System Exclusive Messages.
The editor can work totally offline and can be installed on your desktop computer of tablet or cellphone, or you can use it on the fly from here.
You can also export the Push Push configuration to a file and import it at a later time, building a simple library of buttons configurations.