Thank you for your interest in MyoAnalyst. it is an imageJ (FIJI) plugin to segment and measure size of skeletal muscle fibers.
Please refer to the "MyoAnalyst User Manual.pdf" file in the Documentaion folder.
In case of difficulties using the plugin, create an issue in the following link so we or someone from the community can help you: https://github.com/ZhangHongbo-Lab/MyoAnalyst/issues.