Android Java - Various Tasks - Implementations

Hi. I have been developing an App for months. I am currently needing to add some final implementations to it. Some of this are: 1) Overwrite Audio (with Audio Record). 2) Make the App to have kind of the same visual appearence (or a decent one) in any screen size (currently I am using linear layouts for all the screens, and the problem is that the visual objects in some screens have not so good locations and proportions). 3) Implement Live Volume Detection (decibels) from the Audio received and recorded from Audio Record. 4) Implement a Built-In Subscription Activity which would make you pay inside the App, when selecting a Subscription for 1, 3, 6, or 12 months. 5) And solve some more Issues I am currently having with this App. . If you are interested in this Project, just send me a message. And if you know how to actually implement any of the mentioned implementations, be sure to mention that too. . The prices for each implementation, we will discuss them, besides the details, and we will make an agreement, before starting to develop them. . I require NDA and IP Agreements Signed. . Thank you for your time. . I expect your presentations. .