What are the implications of a majority of CEOs planning for a recession in the next 12 months on the mobile app industry?

Alternative strategies for scenario planning in mobile app development could include:

1. Agile Development: This approach allows for flexibility and adaptability, with regular iterations and feedback loops.

2. Lean Development: This strategy focuses on developing a minimum viable product (MVP) to test market reactions before investing heavily.

3. Outsourcing: If the in-house team lacks certain skills or resources, parts of the development process can be outsourced.

4. User-Centered Design: This strategy involves designing the app based on user needs and preferences, which can be identified through user research and testing.

5. Cross-Platform Development: Developing an app that can run on multiple platforms (like Android and iOS) can increase market reach and ROI.

6. Security-Focused Development: With increasing concerns about data privacy and security, incorporating strong security measures in the app development process can be a strategic move.

Companies like Apple or Google would adapt their mobile app development project plans in response to macroeconomic changes by adjusting their strategies and forecasts. They would likely increase their focus on scenario planning, considering various potential economic situations and their potential impact on the business. This could involve adjusting their product lines, pricing strategies, or revenue models. They may also increase the amount of 'runway' they have saved, to ensure they can weather any potential economic downturns. It's also likely they would closely monitor changes in the macroeconomic environment and adjust their plans as necessary.