legal, copyrightWhen I use an image with Creative Commons license on my android app, can I just add the name of owner to the credits part or should I mention it on each work?
Take a look at the best practices guide from creative commons on how to attribute and what constitutes a good attribution. As mentioned in the guide a good rule of thumb is to use the TASL acronym.
T - Title, what is the name of the material?
A - Author, who owns the material?
S - Source, where can I find it?
L - License, How can I use it?
In addition, each author should be mentioned but you can satisfy the requirements in any reasonable way. So, for videos you can put the authors in credit for images you can add a link to the source etc.
All content is licensed under CC BY-SA 3.0.