Hi, I tested the plugin with WooCommerce 2.1 and two APIs namely Solutions Infini and MSG91
Solutions Infini API is not working. They have changed the API in some way or other. When you talk of support, they just do not respond unto weeks.
MSG91 API is working. Although there are following problems with it:
1. Customer is receiving the new order SMS two times.
2. Store owner is not receiving the new order SMS.
I tried the above on same owner and customer number. Someone else can test and checkout.