Tubi is an Android application for the streaming service with the same name that allows users to watch content without a paid subscription. Read more about Tubi  

Most streaming services are using some sort of a subscription model that helps them provide content to users, but Tubi is trying something different. The Tubi streaming service is ad-based, which means that you won’t need to pay a subscription.
Tubi covers all types of content, ranging from comedies and drama to kids classics, and even covers Korean dramas, anime, and British shows. There is something for everyone.
Users don’t need to add their credit card, but ads are shown, although at a much lower rate than the regular TV programming. New shows and movies are added every week, and people can add them to bookmarks so that they don’ t miss anything.
Of course, Chromecast support is implemented, along with multi-device sync.