Web App touch screen development

I'm needing to create a web app for a project. Basically, it is going to act as a carb counter application for someone suffering from diabetes. I'm pretty confident in building a website and using PHP to connect up to some sort of a database to query it with SQL. However I'm a little puzzled how I'm going to go about developing and testing any touch screen events or even seeing how the app will look on a phone.

I'm pretty limited in the hardware i have (iPhone 6) but I'm wondering if there is some sort of environment that is recommended for app development and testing or if there is a way of easily uploading an app to test on my iphone.