Google Plan: AMP will kill Apps on search
On Google, the plan with the launch of AMP is not only to improve the experience of the users when they are searching on mobile phone. According to Search Engine Land, Adam Greenberg, head of Global Product Partnerships at Google, “said during the question and answer time that AMP pages will override app deep links for the “foreseeable future.”
Google will not stop to support app index, however it will give priority to AMP when it is available.
See here how AMP looks like.