Electromagnetic systems have been used extensively for the control of magnetically actuated ob-jects, such as in microrheology and micro-robotics research. Therefore, optimizing the design of such systems is highly desirable. Some of the features that are lacking in most cur-rent designs are compactness, portability, and versatility. Portability is especially relevant for biomedical applica-tions in which in vivo or in vitro testing may be conducted in locations away from the laboratory microscope. This document describes the design, fabrication, and imple-mentation of a compact, low-cost, versatile, and user-friendly device (the ModMag) capable of controlling multiple electro-magnetic setups, includ-ing a two-dimensional 4-coil configuration, a 3-dimensional Helmholtz configuration, a 2-dimensional magnetic tweezer configuration, and a piezoelectric transducer for producing acoustic waves. All electronics for powering the systems are contained in a compact 10 " x6 "x3 " case, which includes a 10 " touchscreen. A graphical user interface provides additional ease of use. The system can also be controlled remotely, allowing for more flexibility and the abil-ity to interface with other software running on the remote computer such as proprietary camera software. Aside from the software and circuitry, we also describe the design of the electromagnetic coil setups and provide examples of the use of the ModMag in experiments. & BULL; Low cost and portable magnetic micro-robot manipulation device & BULL; Compatible with the 3 most common coil configurations (traditional, Helmholtz, tweezer)