iOS 10.1 beta issues warnings for older, 32-bit apps slowing down your iPhone
The current iOS 10.1 beta update sees the addition of an alert warning users that specific apps – usually older, written in 32-bit code and not updated in quite a while – may slow down their device. It also suggests that the app's developer has to update it in order to improve compatibility.
Apple's idea is to direct users away from apps that still haven't been refreshed with native 64-bit support. The warnings appear upon launching such applications.
Back in late 2013, Apple started urging developers to submit 64-bit applications to take advantage of iOS' 64-bit support and the iPhone 5s' new, at the time, 64-bit processor. In 2015, 64-bit support for apps was made mandatory. Thus, the alert mostly deals with pre-2015 32-bit apps that still haven't been updated to comply with the App Store's 64-bit requirement.
Last September, Apple also began notifying developers that apps which haven't received compatibility updates will be automatically removed in a 30-day period if they aren't fixed. The messages, first introduced in the iOS 10 beta and probably coming to users with the iOS 10.1 update, likely are a part of this campaign.