Icon for "submit and close"

I have a mobile app with a series of task users accomplish through several screens. User performa an action, tap on the bottom-right icon ">" and goes on with subsequent tasks. On the last screen, on the same bottom-right place, I have a "save and submit" icon. I used a "check" icon or a "paper-plane" icon, but users seem not to fully understand them. What kind of icon or CTA would you use in this case?