Can we access a user’s contacts?
Also, can we redirect them to Phone (Application in Android) using just UI???
In Firebase, as we add a new app they ask you for the platform I usually take web application, but their are a lot others like: Unity, Android, iOS. So what happens when I choose them for a Thunkable App, and what is the big deal about them. 
???
Please help me…
Interesting question. I also want to know the answer. But I suspect the back-end native codes Thunkable used to interface with Firebase are using web APIs which is independent of platform language. I can understand why its this way because otherwise, Thunkable need to translate our blocks using Unity, or Java, of Swift …etc…
Exactly, I am making a chat app with the features of Outlook, Skype, WhatsApp, Skype For Business.
So need to have a lot of features, need to access contacts, register huge amount of data into Firebase, redirect users to Contacts in case they wanna add people into their contacts also I need to give warning if the person chatting with, is not in their contacts, thus I need to access contacts and a lot of stuff.
Here is my project link: https://x.thunkable.com/copy/895e9cdad9603a8b8adc508e5fb887e4
Not ready yet need to do a lot of work…
But you can use this as for an idea of what this app is about… 
I hope this project link was of some help… 
This problem has been irritating me for months!!
This is a question not solved by the community yet please help everyone…
The question for firebase troubles me a lot…