try
        {
            ChatMessage msg = new ChatMessage {Body = "C# is the best!!"};
            msg.Recipients.Add("number");
            ChatMessageStore cms = await ChatMessageManager.RequestStoreAsync();
            await cms.SendMessageAsync(msg);
        }
        catch (Exception e)
        {
        //TODO: There I want show user sms app, but do not know how
        }

<Capability Name="cellular" />
<uap:Capability Name="cellular" />
...