There is no option to move the location of the submit button in HTML forms at this time.
I am getting so sick of this service, I am surprised that Adobe let something like FormsCentral be released without some BASIC features.
After playing with conversion tools for several hours, I discovered that my PDF Form was not going to convert to a nice looking Web Form. Next I went to FormsCentral and started creating a Web Form.
At first, I was thrilled with all the great options I can use to create my Web Form until I was ready to test and deploy. I then discovered that the Submit button on a Web Form is placed by Adobe's FormCentral, the user/designer has no say over where the Submit button should be located (you CAN do THIS on a PDF Form). Doesn't that defeat the purpose of FormsCentral? Users being able to CREATE their OWN Web Form?
You should be able to at least choose the submit button and then use the text align icons to choose if you want the submit button on the left side, center or right side or your Web Form.