The HA-Smart app allows you to use your smartphone or tablet to connect to Ha-smart hearing aids or hearing amplifiers. you can then have full control of those devices from the app, so you can customize the sound for your needs and your environmentThis version update something:1 the app scene frame adapt mobile phone with android system 2 when app back to front will connect device again3 modify open Bluetooth tips in EnglishUse the Ha-smart app to :1 control volume in one or both ears2 switch the listening modes3 check the battery levels