You can do whatever you want with Firebase, regardless of payment tier, as long as you adhere to the terms of service .
Read moreCan Firebase be used for production?
We have a lot of large customers who use Firebase in production . The main metric to be aware of are the concurrent users. Basically, how many devices are connected to the app at the same time. The free plan covers you up until 100 concurrent users.7 Oca 2017
Read moreCan I use Firebase as backend?
Firebase provides the best back-end server , great database and analytics solution, and useful integrations with other Google products. Most of all, users like that it’s free to use and has affordable subscription options. A wisely designed backend solution guarantees project scalability and data security.
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