Play with friends, strangers or bots.

This is the de facto standard for apps to play contract bridge. It is stable, reliable, sophisticated, and always available.
You can practice anonymously or log on with a free user ID to play against friends or strangers or even robots (bots). Or you can use it to watch other amateurs or even professionals in major competitions.

Alanrick123 about BBO – Bridge Base Online, v4.0.3