Updates for native app (WalletHub - OAuth2)

I am looking for a developer to make updates to the native app for WalletHub. The app is developed for both iOS and Android platforms and it needs native programming skills.

Key features of the app include:
- profile creation and personalization: users should be able to create their own profiles and personalize their experience within the app.

The right person needs:
- prior experience in creating libraries in both iOS and Android
- prior experience with security involving OAuth2 authentication process and security protocols/frameworks
- experience with creating mobile libraries (pods for iOS, jar for Android) is a plus
- excellent problem-solving skills and attention to detail
- strong communication and teamwork skills

In terms of design, I have specific guidelines that need to be followed. The developer should have experience in adhering to design guidelines and creating visually appealing interfaces.

Ideal skills and experience:
- Proficiency in native app development for both iOS and Android
- Experience working with OAuth2 authentication
- Strong attention to detail and ability to follow a detailed list of updates

Please provide examples of previous work and your estimated timeline for completing the updates.