Very easy to use online form to collect sea turtle data

I am trying to develop an online data collection system for sea turtle sighting data in Cambodia. This includes picture upload, name, date, location, species, information on tags, any measurements taken, if it was caughtin fishing gear, and when it was released (and if not, why not). 

I want to have a link form - we believe that having to download a special app to enter data will prevent people from using it. Previous experience showed some of the people likely to be using it didn't even know how to right-click on a computer. This should be very, very simple, and be smartphone friendly.

It must be incredibly easy to use, and ideally have logic jumps. (e.g. is the turtle tagged yes/no -> skip question/which flipper was tagged + what was the tag number).