The Movie 360 video app is free today. It's got some nice features and worth grabbing. (Normally $4.99) but the best app may be the Camera360 Ultimate, which is by the same developer, and is normally free. I would grab them both. The camera app has some really cool filters and features that add a lot of fun things for taking pictures!
And while we are talking about camera apps... here is another one that is free for the day. (Normally $4.99) Fast Camera – The Speed Burst Camera and Time Lapse Video,App (4.5 stars with 4801 Ratings... so it's really popular and gets great ratings!) Be careful, it will get the pic you want, but can take up to 1200 in one minute!