Logic gate arrays are electronic devices delivering an output voltage which is a function of one, two or more input voltages. Usually, such circuits are made from CMOS subdevices ( transistors) which provide an output function defined by the layout of the device. Thus such logic gate arrays are not programmable after the production and, moreover, they are volatile because inputs and output lose the information after power shutdown. Here, we describe the use of magnetic tunnel junctions for the preparation of alternative logic gate arrays. These devices are nonvolatile, i.e. keep the inputs and output after power shutdown, and they are field programmable, i.e. the output function can be defined even 'on the fly' during the operation. Potential drawbacks such as scalability and reproducibility will be addressed and possible solutions for these problems will be discussed.