Just head to Google Play (or check out the source repo if you're into that).
So what does that app have to offer?
> search (with all the additional parameters available on the booru search page)
> content filters (default, everything, etc.) with spoilers shown for images with hidden tags
> image interactions (fave, upvote, downvote)
> image downloads
> detailed image view (tags, faved by, comments)
> (upcoming release) posting comments