Collaborate on code with inline comments and pull requests. Manage and share your Git repositories to build and ship software, as a team. BitBucket is good for teams who have gone all-in on Atlassian products.bitbucket.org
From project planning and source code management to CI/CD and monitoring, GitLab is a complete DevOps platform, delivered as a single application. GitLab is up and coming, and especially great for its built-in support for testing and CI/CD.
GitHub brings together the world's largest community of developers to discover, share, and build better software. Tried and true market leader for code storage.
Split provides a unified solution for feature flags, experimentation and continuous delivery, centralizing feature flag management. Split has a more complex offering than just feature flagging that includes A/B testing and experimentation. Has a free tier.