#96 #97 #98 and #99 are great designs for sure but unfortunately you won't be able to register any of them. The designer used the images from here : http://designchair.co.uk/vectors/colourful-vectors-for-logos-by-mystocklogo-com/ . Since commercial use is allowed, someone else can also use them and make a logo similar to yours (although the mobile might not be present in it)! Moreover the company that created them , stocklogo.com, no longer exists, so you can't assume that they are free to use since there is no "official license".
One thing i've noticed here is that many designers use stock images which might get contest holders in trouble later. Please be creative and create your own designs completely from scratch.