How much longer do you think app developers will continue to support Android 4.4 kitkat?

I have a Lenovo Android tablet that will not be receiving the lollipop update and it still works great, and I am just wondering how much longer until I start get notifications that apps I like, such as those that stream television, or news apps, etc no longer will be supported? Is kitkat near the end or do we still have a few more years?

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