Background: Creating innovation and change in teaching methods is one of the basic issues thateducational systems face. Using smartphone applications for medical students learning arebecoming progressively prevalent especially during COVID pandemic period. Ehistolab is a novelsmartphone application that is designed for histology education. It is available for iOS andAndroid phones.Methods: Ehistolab application was established using react-native frame-work which is currentlythe highest technology in developing hybrid apps in the world. We used mapping techniques andtiling approaches on histolab photos and made a high resolution efficient user-friendly and fastplatform for medical students. The application is interactive and can engage students in histolabphotos. The efficient method that we used will enable users to have optimize internet and batteryusage on their cell phones and help them to access material lessons at anytime and anywhere.Virtual histology images were produced by a manual microscope true chrome metrics camera andslide scanner and mosaic software. As we change the stage manually the images will attachtogether. The whole tissue image can be scanned in about thirty minutes using a forty X objectivelens. After that all the photos are saved and maintained in our server. On each photo we have pinedimportant parts with assigned descriptions. The description could be the combination of text andimage as well as audio file that explained that section for the student.Results: The application and digital microscopic images is used approximate in June of this yearfor histology teaching to more than hundreds user in the world. Conclusion: This study presents a very helpful mobile application as a support in histologyteaching to medical students during this COVID pandemic time. In fact this application can beused by students whenever they are needed.