We review progress in the development and applications of superconducting nano-strip particle detectors. Particle detectors based on superconducting nano-strips stem from the parent devices developed for single-photon detection (SSPD) and share with them ultrafast response time (sub-nanosecond) and operation at a relatively high temperature (2 -5 K) with respect to other cryogenic detectors. SSPDs have been used in the detection of electrons, neutral and charged ions, and biological macromolecules. Nevertheless, the development of superconducting nano-strip particle detectors has been mainly driven by the use in time-of-flight mass spectrometers (TOF-MS) where the goal of 100% efficiency at large mass values can be obtained. A special emphasis will be given to this case, reporting the great progress achieved which permits to overcome the limitations of existing mass spectrometers represented by low detection efficiency at large masses and charge/mass ambiguity and could represent a breakthrough in the field. In this review article we will introduce the device concept and detection principle, stressing the peculiarities of the nano-strip particle detector as well as its similarities with the photon detector. The development of the parallel strip configuration is introduced and extensively discussed, since it has contributed to significant progress in TOF-MS applications.