To design a prototype for an app using an online tool.
This is a great app prototyping tool
Here are some demonstration prototypes
Mozzilla (Firefox) have their own app tool
Use the links above to build a prototype app. You will need to be on Chrome, Internet Explorer wont work. Also you need to create an account. You can make up an email just remember your username and password.
A more advanced tool is www.proto.io you need to verify your email to activate your account.
You all have an email account on Office 365.
To access Office 365 go to https://login.microsoftonline.com/