WiFi Analyzer is a lightweight application that analyzes the available WiFi networks.
It helps you to evaluate the signal interference of existing networks and find out the less crowded channel

Features:
- WiFi scanner with detailed list of available networks
- frequency graph for 2.4GHz WLAN (802.11b/g/n)
- signal level history graph of available networks
- network router vendor (complete router vendors database)
- 2.4GHz/5GHz band channels
- save screenshot

The ads-free version available at: https://play.google.com/store/apps/details?id=org.hlousek.droid.twapro