I want to have a cozy place where I store all my variables and secrets safely per project per environment. I want to share it with my team, CI servers etc. I want to just specify a single key: the environemnt title. And all the variables should be pulled from somewhere. Is there such tool anywhere on the internet???
Now on a more general use case, I guess there are two types of applications: - Client-side (like Expo): I would not store any "secret" for security purposes, just configuration. You seem to use JS for your client-side so use dotenv packages (https://www.npmjs.com/package/dotenv, https://www.npmjs.com/package/dotenv-webpack, etc...)
- Server-side: Depending on your environment, CI, hosting you might have a different solution, sadly not any one-fits-all solution to my knowledge. Heroku provides a pretty straight forward solution, on my production environment I use a configuration management, Chef's Data Bag but you could as well use a service discovery like Consul, Zookeeper, Etcd, etc...
I hope this is a bit helpful.
But if your ok with storing the keys to your accounts with a third party and the risks that poses, maybe you could use something like git-secret?