One ui 3.1 I install now

[innovativeAR121]

Check it very easy to install 

[innovativeAR121]

Bro available in A and S SERIES

[amelbhatti22]

These features are also missing in A11,A21s,A12 because these handsets are running on one UI core versions..

[innovativeAR121]

Yes bro it's not core version issue it's chipset or hardware not compatible

[amelbhatti22]

But any device in your views which is core based ui and have these options like secure folder and samsung pass?

[innovativeAR121]

Bro you have one ui 2.5 or 3.0 or 3.1 which one ???

[amelbhatti22]

One ui 2.5,
A31..

[innovativeAR121]

Bro A31 has not secure folder

[amelbhatti22]

A31 is not ui core version based,
So it has secure folder,
I am currently using it..

[innovativeAR121]

Bro every phone has core version remember it

[innovativeAR121]

Read my comments I said A series has secure folder and it's not depending on core version it's depending on chipset and hardware