Need to be rooted.
Do you have a U or a U1 device? I'm on the never software version so I don't think I can bootloader unlock my U device anymore in order to root it..
I had same issue. Uninstall and install from galaxy storeI have version 33.5. I cleared cache and when that didn't work I uninstalled and reinstalled it. Still silence. Now I don't see it under my accessibility settings nor any way I can add it on there.
The wierdest thing is the first time you install it, there is a notice that says it might not work properly on my phone and that I should install "ACRPhone our new free call recorder etc..." Choosing that takes you to a completely different app and I'm not willing to go there from what I've seen so far..
I have a U1 device and yes it works on both up and down stream. I haven't gotten around to testing on Bluetooth, though. I'll give it a shot and report to you on how it works.Great.. Do you have it working on a U or a U1 device? Apart from not working over wifi, how is the overall call quality? Does it pick up voice/ sound from the other party equally well? Does it also work over bluetooth/ wired headsets and VOIP services like Viber and Whatsapp? Lastly, can you share a link and the app version you're on?