What are the advantages and disadvantages of using cell phones in the classroom at university?

What are the advantages and disadvantages of using cell phones in the classroom at university?

Planning and writing an expository essay ( Explain, provide info, problem and sollution/compare and contrast/pros and cons) (650-750 words). Planning (brainstorming, organising, outlining), Writing (introduction, body paragraphs, conclusion). Use no references. Write from your own knowledge.