Pixton is a great free tool for creating comics

Go to http://www.pixton.com/uk/ > login > select Connect with Google > Google will ask you to allow this site

If it is the first time you are logging in you will need to create a pixton screen name, you can do this by selecting “I don't have a pixton screen name” if you haave already created a screen name click on “I already have a pixton screen name”