Evgene,
I have some information from Google Play as to why the app is not available in the Google Play store for tablets. Apparently, I have a telephone number that is linked so you can call us if you tap the button. How do I set this up so it is available for phones but the button disappears if the app is used by a tablet? Here is the response from Google Play...
"Hi Jay,
Thank you for your message. I understand you're unable to find your app on an Asus Transformer Pad TF300. The reason is because your app is incompatible with the TF300, as indicated by the Developer Console (please see screenshot). Please note that you can check this list at any time to see whether your app is compatible with any device, as well as manually exclude any devices if you wish.
The reason your app is incompatible with the TF300, and probably many other tablets, is due to the app's following features:
android.hardware.location.network, android.hardware.telephony
As you may be aware, the TF300 does not support features like making phone calls. If you wish to resolve the compatibility issue, you might want to remove these features from your app's manifest.
I hope this helps resolve your inquiry. If you have any other questions, please don't hesitate to let me know."
Regards,
Ed
Google Play Developer Support