Hello,
I understand that you have an existing application that needs to redevelop and upgrade to resolve the issue in the current version. Kindly, share the APP along with the list of the bugs and modification that need to be resolved in the new version of your app.
It will be great if we can have a small but detail discussion here on freelancer so, I can share my understanding for the job. Looking forward in anticipation to your response.
Warm Regards,
Arvind