This happened to me today, I found old project codes without SQL dump. Just want to check if project is still reusable. Following are the two ways you can recover database schema from FRM file.
Using mysqlfrm utility by oracle
This is pretty handy command line utility from MySQL Team. Check out the official Documentation.
Online version of mysqlfrm
This is not official one, but TwinDB team created Database Recovery portal to generate schema from .idb and .frm files. Must be using mysqlfrm utility behind the UI.
This log is for future reference purpose, If you have any other tool, please mention it in comments.