How is the licensing of posters and frames from films in the android application (for google play)?

Question

Android

The application is something like a mini encyclopedia of movies and TV shows. Naturally, it is planned to use posters from movies and TV shows as pictures in the description section. I don't want the app and account to be banned due to licensing issues with this content. Do I need to obtain licenses for this content? How do various online cinemas and applications similar to movie mania get out of this situation?
The pictures themselves will not be stored in the application and will be downloaded via the Internet when watching a particular movie.