Hi! Could you please help me with Tiggzi/Parse.com tutorial/example:
Regular users could post questions to admin.
Admin user could comment/answer on them.
User can only see her/his posts and related comments.
Sounds simple, but I'm just a beginner 
I recommend you first try this tutorial, it will give you a good idea how to connect to Parse: http://help.gotiggr.com/getting-start...
As for your app, you would need to add permissions to the data you save
Hi Max! I've already tried this tutorial. But in my case I suppose I first need to design proper data model (relational). This is where I'm stucked right now 
I have User, Question and Answer classes.
How exactly to bind them?
How to fetch relational objects data for display?
I've succesfully created user and have it signed into app.
Thanks again!
Check Parse docs, they support relations in their database.