Recently developed tunable MEMS Fabry- Perot interferometers based on Ag thin-film mirrors have enabled building highly miniaturized spectral imagers covering almost the complete VNIR wavelength range. The level of miniaturization required by modern smartphone industry has created extremely compact, high performance electronics and camera technologies and by utilizing these technologies together with the novel MEMS FPI's, it is possible to create extremely compact spectral imagers while still achieving good performance. This paper presents a spectral imager design that can be fit inside an envelope of 1 cubic inch (25.4 × 25.4 × 25.4 mm3) and it will be capable of recording images at freely selectable wavelengths within the range of ca. 650 nm - 950 nm. The imager field of view is ca. 12.5° × 10° and the image size is 640 × 512 pixels. Nominally the imager will be focused from ca. 0.5 m to infinity, but with additional optics it is possible to use the imager as a microscope. The compact size of the imager allows the easy integration to almost any available platform, including small drones, nanosatellites or planetary rovers, where small size is essential. It is also possible to integrate the imager to handheld devices, so the potential field of applications will be extensive.