Nokia has essentially declared the death of the operating systems Symbian and MeeGo, announcing no new content will be published on its app store from 1 January 2014.
The company told developers they had just three months left to update content.
The email outlining the timetable reads: "If you have Symbian and MeeGo content in the Nokia store, it will continue to be available for download to customers, and you will continue to receive download and revenue reports as well as payouts for downloaded content.
"However, starting January 1, 2014, you will no longer to be able to publish any new content or update existing content for Symbian and MeeGo."
Microsoft bought Nokia's mobile phone business for 5.4bn euros ($7.2bn) last month.
The purchase is set to be completed in early 2014, when about 32,000 Nokia employees will transfer to Microsoft.