Ad-free Android App Developer

I require a skilled Android developer capable of creating an application with in-app purchases. I am interested in offering a subscription service that gives users an ad-free experience. Expertise in the following areas are preferred:

- Android development
- Integration of in-app purchases
- Proficiency in developing subscription services

The perfect candidate understands user-friendly interfaces and can ensure a seamless purchase experience. The subscription service will just remove ads from the app. Please ensure your bid includes an approximate timeline for the development of this feature.