You can sync as many folders as you want; this client makes it easy to directly upload any files you want to share, with no limit on the number of folders that you upload at the same time. When you install the client on your system, it will automatically create a directory in your MEGA account and another on your PC, and from that point on they will be synchronized.
Through the app you can configure preferences for uploading and for your account itself, like the language, and access a summary of your account, even establishing transfer limits.
MEGASync provides you with everything that you need to administer your MEGA account. It's the best alternative out there to Dropbox's 2GB, as MEGA offers 50GB.