In addition to the packs provided with your Moviestorm licence, and in the Marketplace, there are loads of mods available from other Moviestorm users.
Below is a list of a few contributors - it is not an exhaustive list. Some are free, some cost money, and the quality varies wildly. Some may require you to have specific content packs or versions installed in order to use them, but they offer great opportunities to extend your Moviestorm filmmaking.
There's no central repository for mods, but here are some places to look. This isn't an exhaustive list - let us know of any others we don't know about! The new releases section of the modders' forum is a great way to find out what's new and who's building what.
Please note that third party mods are not supported by Moviestorm. Not all mods will work on all versions of Moviestorm, and some mods may not be compatible with others.