The free version of SolveBoard includes everything but File Upload. With File Upload you can upload up to 5 files to some Elements like Notes, Pictures, and Talk Elements.
With Storage Elements you can upload up to 100 files to a single Element. This is a great way to consolidate and visually organize large numbers of files on the Cloud.
You can access your Account from the menu bar on the main pages. When you are in your account you have several options, including Subscription Plan. There you can update payment information or make a change to your plan as needed.