Wireframing is a highly important step and facilitate developers and designers to plan the whole application layout. It also highlights how users will interact with the application. Think of it like a black and white blueprint of your application. Based on this blueprint developers will build the actual application.
There are hundreds of different tools available for creating wireframes. You can use any tool which you feel comfortable with. Most professional designers prefer Adobe Photoshop and Illustrator but there are many other tools that are dedicated to creating wireframes such as:-