If you’re a developer, you might need to update your apps.
The Google Play Store is filled with apps that are vintage and haven’t been updated in months, maybe even years. It could be because the developer simply doesn’t care, or the app just works and there is no need to update. However, starting from Android P, that will change. The minimum API level for Android P is v17. In other words, Android 4.1. Why tho? Security flaws is one reason. And, as Android evolves and keeps getting updated, the OS gets new features, like Doze in Android 6.
How exactly will this roll is still unknown. Right now, you simply get a message when you turn on the app that it was made for an older version of Android and it might now run well. However, the developer documentation for P states, “Applications targeting lower values will fail to install and run.”
It would be nice to see Google put some pressure on app developers to keep their apps updated, something like Apple does.