In the furnace I can´t put coal

Put the summary of the bug you're having here
Well, I was playing the 0.7.0(alpha)
and I put some sand in the furnace and I wanted to put coal to make glass and I cannot get my sand and put coal, I had to mine it by force.

What I expected to happen was...:
Describe what you thought should happen here
I thought that was my iPhone screen.

What actually happened was...:
Describe what happened here
That was a bug and I read the summary at the app and they said the same thing tha happened to me.
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...