Correctly incorporate Geofencing to an iOS app and create an Android version of the same app

We have an iOS app that is about 80% functional. We have source code for this (two iterations). However geofencing has not been implemented properly in this app and we now need a developer with expert geofencing knowledge to review the existing code, fix it where necessary to incorporate geofencing as per the original scope. Once the iOS app is completed and ready to go we then want an Android version of the app developed. The Android version is only to be started once the iOS is complete and working satisfactorily. Maybe can even be a separate project after iOS is complete but we want the same Freelancer team to support both apps ongoing. We can discuss in more detail with successful shortlisted applicants in terms of budget. For iOS completion we expect only a few days work should be needed by an expert to complete this. Responses should clearly define iOS completion and Android version costs as separate items for Milestones.