Cellphone-based microscopes attract significant attention due to their application in portable and lightweight systems operating without heavy microscope stands and bulky objectives. However, the resolution of cellphone-based microscopes is typically pixel-limited due to insufficient image magnification. An increase in magnification usually comes at the expense of field-of-view (FoV). In this thesis work, we develop cellphone-based microscopy by integrating cellphones with high-index ball lenses placed in a contact position with the investigated nanoplasmonic objects. Due to extremely high additional image magnification provided for real or virtual images depending on the refractive index of the ball lenses, a significant resolution advantage over more conventional systems was realized allowing in principle to overcome the pixelation problem and to make a step towards achieving diffraction-limited resolution by ordinary cell phone. It is shown that this goal can be achieved using ball lenses with a specially designed index of refraction, typically being sufficiently close to an index of about two. To increase FoV, we developed the technology of thermal pressure embedding of highly ordered arrays of ball lenses with different diameters in plastic coverslips. For the same purpose, we developed technology for translating ball lenses along the surface of investigated samples followed by stitching corresponding images. The resolution of cellphone-based microscopy obtained through movable ball lenses is estimated to be at approximately 1.5 μm level, but we see potential to reach the diffraction-limited resolution over a millimeter-scale FoV by the cellphone-based imaging in future studies.