Income Expence Management Mobile Application

I'm looking to develop a mobile application focused on income and expense management. The primary function of the app should be to track income and expenses. Users should have the ability to categorize their transactions by predefined categories such as food, travel, etc. Additionally, it should allow users to create and add their own custom categories.

Key features should include:
- Tracking income and expenses
- Categorization of transactions
- Ability to add custom categories

Ideal skills and experience:
- Experience in mobile app development (iOS and Android)
- Strong understanding of finance-related applications
- UI/UX design skills for a user-friendly interface
- Experience with database management for tracking user data
- Knowledge of security measures to protect sensitive financial information

Please provide examples of similar work done.