UPDATE 3/26/2020: If the website below does not work for you, try this one instead.
myRebus is a fun tool that teachers can use to create picture sentences for students to solve. For example, I made the one below for the students who signed up for my summer Google Classroom. Can you tell what it says? The site allows you to type in any sentences and it will generate the rebus for you. It does ask for you to input your e-mail to have the rebus sent to you, but I just take a screenshot. This could be a fun alternative for spelling practice or even a strategy to get students to pay attention to directions on an assignment. Another great use is for Breakout Edu clues! For students who want to create rebus puzzles, they can use this site, or you might want to take a look at this lesson plan I wrote for Canva.