Estimate the number of apps available in the Play Store.

To tackle this guesstimate, start by breaking down the problem into manageable components. Consider the growth trends of app development over the years, and think about the average number of new apps added per day or month. You might want to reference the total number of downloads or active users to gauge the demand for apps. Additionally, factor in the percentage of apps that are removed or become inactive. Use these insights to arrive at a reasonable estimate, and be prepared to explain your assumptions and calculations clearly.