I think this would be a great tool to use after you've already created a video. It seems like Scrapblog is geared more toward making the digital story visually appealing. It's completely web based and very easy to use! You can choose from themes, create your own using stickers and backgrounds or use a mixture of both! What I really like about Scrapblog is that it connects with your Facebook and allows you to download pictures straight from your Facebook page and then upload your finished Scrapblog to your Facebook when you're finished!
Though it may not be the best tool for creating a video, it would be a lot of fun to spruce up an existing video you created using another tool.