To be fair, I think Horizon is one of the more promising Firebase alternatives. However, it has completely different semantics, and is quite immature at this p

To be fair, I think Horizon is one of the more promising Firebase alternatives. However, it has completely different semantics, and is quite immature at this point (look at the limitations: http://horizon.io/docs/limitations/ http://horizon.io/docs/limitations/). But if Firebase remains proprietary and Horizon continues to improve I could certainly imagine that rewriting my app will eventually start to look attractive.