Recently I retrieve the information of videos which should be played on the Android apps with Youtbe V3 API. The problem is some of them are not avaliable on the mobile devi
There are two concepts embeddable and syndicated. iOS devices use iframe so they basically embed. Android devices that use player API can check syndicated.
When you do a search->list, you can set videoEmbeddable and videoSyndicated to true.
Or if you are iterating through videos, for each video, you can do a video->list call with video id and check status.embeddable in the response.
Here is a blog post about this topic, even though examples are in v2, information is still relevant.