Offline Turmeric Purchase App

I need a small, single-user Android application called “Bhavit Halad Kharedi” that I can run entirely offline to track turmeric buying transactions. The workflow is straightforward: each time I purchase turmeric I must be able to enter the purchase date, trader’s name, weight in quintals, and the rate per quintal. The app should instantly calculate the basic cost, then let me add transport, hamali, brokerage (as a percentage), or any other expense so the total cost and the final cost per quintal appear automatically.

Because I will open the app many times a day in the market, the interface has to feel clean and quick—nothing fancy, just a moderate design with a tidy layout and a few helpful icons so buttons and fields are easy to spot on a small screen. Records only need one simple filter: I should be able to view past purchases by choosing a date range, and of course edit or delete any entry if I made a mistake. All data stays on the phone; no login, cloud sync, export, or sharing features are necessary.

Please send:
• the installable APK
• full, well-commented source code
• short install/run instructions (enough for me to rebuild if I ever change phones)

I work on a fixed-price basis and prefer breaking the work into milestones so I can test the APK on my device before final release. Let me know your total price and how many days you need for delivery.