Network Tester is a free Android application developed by Guillaume Cottenceau, categorized under Utilities & Tools. The app is designed to quickly validate whether your device is connected to the actual internet or if it is being redirected to a billing portal. This is done by downloading a small dedicated file and checking its content. The app also offers troubleshooting features to validate hostname resolution and TCP connection for any data connection.

Additionally, Network Tester provides statistics on internet speed by allowing users to measure downlink speed on HTTP downloads of 10K, 100K, and 1M. Furthermore, Network Tester is open-source, allowing users to access and modify the source code. Overall, Network Tester is a useful tool for anyone wanting to verify their internet connection and troubleshoot any connection issues they may be experiencing.