I need an app developer

My name is Shreya, I am looking for someone who can create an app for my NGO For mental health awareness .The app needs to be student friendly and efficient, should have options for messaging and chatting and being able to book slots with our professionals on board .should also have an option of switching to professionals where they will enter their id or something like that and input their free slots . Even track their progress and have other services like meditation or any activity which eases their headspace .