SMSBOX is a tool to send anonymous messages, written by TrollSkull, this script uses the Textbelt API to work, Textbelt is an API that allows us to send a single message per day on a single IP.
You can download SMSBOX on any platform by cloning the official Git repository:
$ apt install -y git python
$ git clone https://github.com/TrollSkull/SMSBOX
$ cd SMSBOX
$ python smsbox.py