PHP flow builder

I have a Laravel CRM that has a simple auto-responder feature based on sequence of replies and keywords. I am considering implement a flow builder for this tool. I need a developer that has had experience with flow builders. I dont need any fancy features as my form that create the responses if very straight foward. No conditional replies, just select next flow step based on keywords or numbers. I want to see some example of the work done in similar jobs or suggestion of flow builder used.