I am an active BB10 native developer, currently creating my second app for BB10 native, I may not be able to write complex Java code, but sure i can read it. My first app is in my profile.
Unfortunately i will not be able to start until this sunday (31/08/2014) because I have to move to the city I go to University.
Not knowing the app to port, the 15 days are just a vague estimation, it could be less or more, depending on my free time (i have exams all over september) and the complexity of the project to port.