This trick is very simple.You dont need any apps for this trick. Just follow the steps and your work will be done.
1. Create a folder of any name like itweet
2. Move the files you want to hide.
3. Now just add the extension .jad like if you have itweet folder rename it to itweet.jad
4. Now create another folder in same directory with the same name but different extension of.jar (example:- itweet.jar)
5. now your main folder (with .Jad extention) will hide and it will not be shown.To see the original folder rename the visible folder (of.Jar extention) and your hidden folder will appear.