Stranger Pings allows you to send messages to people on WhatsApp / SMS without saving their numbers to your contacts.
Question:
So what? There are plenty of apps that do it!
Answer:
This app is absolutely similar to those apps, except...
1. Stranger Pings is blazingly fast because the UI is coded purely using Java.
2. It's also damn small in size (180 KB) (also, TWSS)
3. No permissions are asked from you. None. Not even the simplest internet permission!