Which HU are you using now?

I'm using Easy connection app (downloaded from Google play).

If i'm not mistaken, joying is not available in malaysian market / car accessories in kl as from my observation 

Easy connection is a ready apps in my HU.
which android version are you using now? is it 8.1?
if not in the apps list, try download it via google play in your HU.
then install on mobile phone.

not all android phone are supported. some models need to use wired connection
It does have wifi connection to connect from your mobile hotspot.

yah.. all the features i've mentioned previously is more to gimmick / selling point.
I'm not fall into that gimmick 
but when I tried branded HU such as JVC and pioneer, i can see the lag-iness when scrolling / play around . which made me feel confuse because their price is higher than android HU, but their version is older (android 6 and below) and not smooth.

I've got the same feeling as you about sound quality before install this android HU. but my unit come with DSP and i can tweak EQ even more from original HU.
some android HU didn't have DSP , therefore you have limited range to adjust your EQ.