Android Audio, Radio frequency and Spectrum Analyzer - SciChart
Portable tinysa Spectrum Analyzer - AURSINC V0.3.1 Hand Held Frequency Analyzer | 100kHz to 960MHz MF/HF/VHF UHF Input | ESD Protected Function & 2.8 inch Touchscreen | Signal Generator: Amazon.com: Industrial & Scientific
RF Analyzer - Apps on Google Play
Turn Your Android Phone or Tablet Into An Audio Spectrum Analyzer
Android SDR with Spectrum Analyzer and Waterfall display