The MoboPlay is free to download and use. I've checked the official website and even installed a copy to test it. You can download all the applications listed within the software in form of an APK installer and then connect the physical device (tablet, phone) to transfer the APK.
You will have to enable Unknown Sources in the Security section of your phone to be able to sideload APKs that were downloaded through a third party application. Also, you don't need an account to download those apps.
Here's how it looks with an application downloaded: