Greetings sir,
to our understanding this should be somewhat simple alteration of the already existing application.
Should be fairly quick work, but we'll need more data, app itself etc..
We are group of 6 iOS / android devs, working on various projects, so this should be no problem to fix. Do keep in mind our amount of free developers variate, so the sooner you decide if you want us to work for you, the better, otherwise our team members might be assigned to projects already.
If you have any questions please do not hesitate to contact us.