The Pocket Pinger
What Does Gold Sound Like? 22k Gold 'Ping' Test [SOUND ON]
16 Tests to Spot Fake Silver Coins - Silver Monthly
CoinTrust app - gold/silver coins and bars sound verification for iOS and Android
Yankee Stacking
Still the best coin Ping Test App
Silver & Gold Coin Ping Tester Review!
Silver and Gold Coin and Bar Ping Test Tool
Fake Gold Coins - How to Tell
50 Piastres Silver Coin from Egypt - Ping Test
Gold and silver magnet test