Hello,
I am up for this job and would be happy to assist you for long term as I carry 3 years of Xamarin based app development experience. I have gone through the list of issues you shared in job description and can fix them for sure. I am also having good experience working with HTML5, CSS3, writing end points, REST, SOAP, PARSE, JSON etc.
I have developed Xamarin apps for various domains and can ensure you quality work
I can also show sample codes, backend of the applications if required.
Kindly get in touch with me so that we can discuss this further and proceed further.
Look forward to hearing soon from you.
Thanks,
Parminder