Develop a native "tasks management" application for Android and IOS, also a matching website

i'm looking for a fullstack developer that can handle complex functionalities of multi tenancy, multi level permissions and sharing, and multi design scheme. the developer will need to control all the abilities of creating a native android application, a similar native application for IOS, and a website with the same functionalities. the developer will need to control the different languages and complexity in a way that he will need to receive tasks on building the different parts of the code (user management, admins functionality and interface, database queries and functions) from backend to frontend. the main architecture and structure of the code will be discussed and will be built accourding to the requirements of future functionality that the code will need to be prepared for. the developer will receive design meterials from me and will need to use them accourding to the mockups he will receive as well. so the main job here will be to code. all parts of the code and other meterials related to the project will be my own intelectual property. the developer will need to sign NDA agreement, and in case there will be compatibility between us, i expect the developer to work full time until the project will finish. i estimate this project can take around 2 - 4 months of work, depending on how fast the developer will be able to get the different functionalities working. if you are going to bid, i'm expecting you to prove me somehow that you can take such a big project of a few months of work, stand in the professional requirements, of operating in such environments. if you have projects you've already accomplished, it can help me decide. the developer that will work on this project must keep the work to himself and not involve other developers and expose the project.