Thank you for your e-mail.
Store Manager allows you to manage as many stores as you wish. You just need to set up the store connection with your other stores.
Please, also download this personal release and install it (you should simply close store manager, download and run this installation file and re-open Store Manager):
https://www.dropbox.com/sm/create/opencart-manager-full-setup-1.3.2.145.exe
Warning: The link provided above is a personal release for a particular user, created due to his request.
Let us know, if you have any other questions.