You could create a debug page where you can call your microflows directly. If you need parameters, create a non persistant helper that you can fill with data in a popup and then call your microflow with these attributes.
To know if the microflow is doing what it's supposed to do, is also a good case for unit testing. Although not suitable for once time testing/checking, in the long haul could save you time and automate your check time and time again.
You could create a rest service that calls the microflow within the application, so you can call it by browser or postman.