I have developed an app using Rhomobile, which is a cross-platform native mobile applications using web-technologies: HTML, CSS, JavaScript and Ruby, but unfortunately now I don't have the source code as I've lost it, but I have the apk that I built at the time. several readings shows it is possible to recover it by reversing the apk which I did but then in the assets\apps\app I got YARV-bytecode which definitely requires to be restored to the ruby source. I saw some tools like reversal which advertised as YARV to Ruby but didn't worked for me. in the examples reversal given YARV-bytecode appeared there are somehow different to those I found from the apk I pulled from.
Mine is a shown below:
How can I recover it?
Please help this.

No it is not possible to recover the code.