Software developer Adobe has effectively killed off its Flash Player for Android, on Thursday pulling the browser plug in from the Google Play marketplace.

The move had been expected since late last year when Adobe declared that it would cease development of the plug in for new mobile devices, as it looks instead to contribute more aggressively to the development of HTML5.

“We announced last November that we are focusing our work with Flash on PC browsing and mobile apps packaged with Adobe AIR, and will be discontinuing our development of the Flash Player for mobile browsers,” Adobe said.

Users who already have the plug in installed do get to keep it however. The software is expected to behave “unpredictably” on Android 4.1 Jellybean, as Adobe has not tested on the platform, so starting this week the company is using configuration settings in the Google Play Store to limit continued access to Flash Player updates only to those devices that have Flash Player already installed. “Devices that do not have Flash Player already installed are increasingly likely to be incompatible with Flash Player and will no longer be able to install it from the Google Play Store.”

Adobe said it will increase its investment in HTML5 and wants to innovate with Flash where it can have most impact for the industry, such as advanced gaming and premium video.

The company admitted that HTML5 is now the best solution for creating and deploying content in the browser across mobile platforms, and said that it will focus on working with key players in the HTML community, such as Google, Apple, Microsoft and RIM, to drive HTML5 innovation they can use to advance their mobile browsers.