Wordpress Plugin & Membership Site Development

Hi Freelancer, we're an online marketing agency from South Germany (near Munich) and looking for a professionell wordpress plugin developer. What we want to realize: An online tool which allows users to create some kind of tests/quizzes (further information and examples via PM), where the results and the inserted data are stored, so that our clients can analyze them. This tool should be embedded in a Wordpress Membership Site with various options to provide the solution to customers. We'll provide an theme for the website, so that you can focus on the membership area and the functionality of the plugin. Clients can select one out of 4 (intern 5 in total) packages, buy the service and pay the monthly fee or the one time costs. Then they get their account detail for our site, log in and create 1 or more tests in the backend, analyze stuff and manage the tests. The integration of the tests in the website of the clients should be independent from the CMS, perhaps just framing. So the clients don't buy the plugin, they pay for the SAAS and the plugin and the accounts with the tests of the clients are running on our site. Further information about the functionality - WordPress membership site: the customer can choose between different options. These options differate in the number of the tests, which can be created, maybe in the design of the tests (an advanced option maybe includes some kind of templates) and in the possibility of support - so the user is choosing a service and is entering the backend of the site (would be awesome if this could be SSL). There he can create new tests or change/evaluate actual tests - if a user has created a test he can insert the test via iFrame in his website (or do you have any better ideas?) - there's a tracking of the data, which are inserted into the tests by different users - our solutions should be multi-language ready and cause no problems during upcoming WP updates - maybe there's the possibility to offer some kind of templates for the tests - one user can create a number of templates, according to the choosen option - our solution should be extendable: therefore we're looking for a partner, which provides us professionell solutions even in the future - the design of the tests should be changeable, so that the user e.g. can select the color of the border, etc. - we need the full accessible code after the work is finished - we need all rights for the code, so that there won't be a problem with changing or selling it - the solution has to have an intuitive, clear design. We will provide some mockups for this and can do some CSS styling - it should be possible to update our solution (e.g. if some new features/templets/ etc. are available) without losing the data of our customer - we need a backup function - the solutions should be scalable for many users - option: a guided tour through the programm, like at the SEO YOAST plugin I hope this description works for you atm. For the development we'll provide some drafts to minimize communication problems. We set value on: - your skills: so please provide us some links to Wordpress Plugins which you have developed and design elements, if possible - a qualified implementation according to our drafts and concepts - no compromise regarding technic, design or functionality (also we know that there is always more than 1 solution) - a proactive communication in fluent english or german - programming within the calculated budget - project starts in September - the project should not take more than 8 weeks - interest in upcoming projects and enhancements We're looking forward to your responses!