Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.

App-Ray - App-Ray provides a cutting-edge solution for you to conduct a system-wide analysis and detect vulnerabilities in your mobile applications.

PCAPdroid - PCAPdroid is an android app to capture the phone traffic and analyze it remotely (e.g. via Wireshark). The traffic can be easily downloaded from a remote device thanks to the integrated HTTP server, or streamed to a remote UDP receiver.

Ostorlab - Ostorlab scans your web or mobile application and provides results showing threats and privacy issues.

Ettercap - Ettercap is a suite for man in the middle attacks on LAN.

Traced for Android - Traced is a free cybersecurity app for Android. It detects suspicious activity from apps and unsecured Wi-Fi connections that might be used to spy on you or invade your privacy.