Some devices ie. Galaxy Tablet 10.1 can only send SMS, but cannot call. Some other devices like Asus Transformer don't even have SIM card.
How can I detect if device can makes calls? And how can I detect if device can send SMS?
Maybe you can query the PackageManager whether the system contains any component that can respond to ACTION_CALL and ACTION_SENDTO intents? You might need to add the "tel:" and "smsto:" scheme in the URI.