A solid easy pairing speaker. It isn’t necessary to use the app. There is no equalizer function in the app for the charge 4 anyway.Edit 1: it is easy pairing - but after pairing when i walked 15 feet away all connection would drop. No music. Would have to re- pair.The Amazon music app has an equalizer function built in that allows you to configure custom levels for each song, even during a song. And the charge 4 is perfectly responsive to the Amazon music app equalizer. So no need for the jbl presets to limit your music style.I bought the 4 because it has the 3.5 aux input. Charge 5 does not. The aux input is a more steady, stable and stronger signal than any Bluetooth. And the sound quality is superior. In addition the battery will last longer.This charge 4 uses an older version of Bluetooth. That is not an issue because all 5 range bluetooth is backwards compatible to 4. I’ve had no problem with Android or ios or kindle fire connections.Edit 2. Distance is an issue if you pair and walk awayI’m happy listening to everything on this. Most of my music is piano, orchestral and folk. I alter the preset in the Amazon music app or my device equalizer. This is not just a boom box. But it can definitely boom a deep enough bass on the factory presets.Fast pairing on all devices, great loudness, good sounds that i can alter with my own equalizer. Works for classical or jazz, too. Including symphonies. Not hi fidelity or stereo but very pleasant. Good price.Connects to other jbl connect devices. Has 3.5 aux.I liked it so much i bought it a carrying case.Edit 3: i returned the Jbl charge 4. Now i have an empty jbl charge 4 case which i will use as an ugly purse.