Write an Android application

Looking for an Android app to start and stop a timing function with a physical button connected to the audio (mic) input/ output jack. This function is to record time on a specific project when said button is pressed and released. This data is then pushed to a database hosted online where it will be accessible to a website which will be updated with this data. This timing function is for piecework in a production shop and is to record the time it took to make a given item (selectable from a dropdown menu), and display the : 1) number of parts made 2) last part time 3) average part time 4) fastest part time 5) fastest times that other employees have gotten in the past for this project This data above needs to be pushed to the database online, but also available on the app. The app needs to have a user login for each employee, and a reports section where the recent data of all employees is available for all to view. Looking only to have the app created at this point, not the website. This application is to be optimized for tablets and does not need to be on Google Play store. Also Google Play service will not be needed for this application. We also considered facilitating our need via a website, and using a tablet simply as web browsers. If somebody has a good idea on that we would be interested as well. We are hoping to get something implemented within the next month whichever solution we choose. See this project for our thoughts on doing it with Special Purpose "arduino" type controller and display: https://www.freelancer.com/projects/HTML.1/Manufacturing-Workstation-Piece-Counter/