Customizing excisting app

We have developed an app called "HSEQ" which is available for iPhone and Android. The app is published in App Store and Google Play, and from time to time we need to update this with new features etc. But, what we will need most help to, is to customize the excising app for clients who wants their own, special version of the app. Basicly the work needed is to change the UI (colors basicly and insert client's logo), change values in dropdown menues, sometimes change names of files or reduce or add files etc. Also there might be some work on customizing text in the e-mail, pdf and xml-file which the app generates. Read more at our website www.mellora.no. We will also need to develop the app for Windows phone in the future, but the most urgent it to get connected to people who can help with the customizing tasks. Very easy work, nut we require the developer/designer to be PROFESSIONAL as we work against large customers world wide. Send me a PM for me info if you require it. The amount of work/projects will vary from week to week, but the future look bright regarding how many prospects we have already in January 2013.