Modify Android APK — Add Client-Side Rate Limit for Login OTPs (Vehicle OTPs Unaffected) — Payment Only After Successful APK Testing

Job ID: 39954539

Budget: ₹1,500 – ₹12,500 INR

I have an Android app (APK) that currently allows unlimited login OTP requests to the server. I want to add a client-side configurable rate-limit feature for login OTPs only so the app will block/suppress additional OTP requests that exceed the configured threshold inside the configured time window. Vehicle-related OTPs must remain unaffected (no rate limit).

High-level goals:

Add a settings UI where the user (or admin) can choose the rate-limit policy for login OTPs: options such as disabled, 1 per hour, 2 per hour, 3 per hour, 4 per hour, 5 per hour, or a custom numeric + interval setting.

Provide a manual Reset option in settings to clear the OTP counters immediately.

Implement robust client-side enforcement: when the rate is exceeded, the app must not send further login OTP requests to the server and must show an appropriate friendly message (e.g., “OTP limit reached — try again in X minutes” or “Reset or change limit in Settings”).

Keep vehicle OTP flows unchanged/unlimited.

Ensure app is re-signed properly and remains functional.

Provide unit/integration test cases and a test build.

Required skills

Proven experience reverse-engineering and modifying Android APKs (smali, baksmali, dex2jar, JADX, JADX-GUI).

Strong Java/Kotlin skills; experience with Android SDK and UI modifications.

Familiarity with APKTool, apksign, jarsigner or apksigner.

Experience preserving app signatures or re-signing in compliance with owner’s use.

Experience with saving secure local state for counters (SharedPreferences with secure mode, encrypted storage, or other secure persistence patterns).

Experience writing test builds and writing test cases for Android UI and network flows.

Good documentation skills and ability to provide clear patch/steps to reproduce.

Prior freelance experience and positive reviews preferred.

I need an experienced Android APK reverse-engineer / developer to modify an existing Android APK.
Currently, the app allows unlimited login OTP requests.
I want to add a client-side configurable rate-limit feature that restricts login OTP requests per a user-defined schedule (e.g., 1/hour, 2/hour, etc.), while keeping vehicle OTPs unlimited.

Important payment condition:
I will not award or pay the project upfront.
The developer must first provide a working demo or test APK build showing the requested modification.
Once I test the APK and confirm it works as expected, I will then award and release full payment immediately.

Bidders must confirm they agree to this testing-first condition.

my budget is 2000rs