Iphone Subbing for Computer

In teaching ESL I have become accustomed to using many tools on the computer for teaching and learning purposes.  Now, however, I am going to be teaching a f2f class where the only technology possibly available to students will be a smartphone.  So I am now doing research to answer the following questions regarding smartphones:
1.  Can you blog?  If so, can people record comments?
Yes, it looks as if you can blog and upload media to your blog.  so I have started a new blog ESL Webtools on Word Press.  Although I am more familiar with Blogger, I couldn't find any smart phone app.
2.  Can you tweet? If so, can you insert pix and voice?  Can people comment?
Ok.  I can access my Twitter account with a Twitter app, but now I need to create a new twitter account just for teaching purposes.  Can I have two?

3.  What games are available?  Are there versions for all brands of smartphones?

4.  Can I create Quizlet games for my students to use on their smartphones?  All phones?

As I find the answers to some of these questions, I will post them.