<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>ryanworl</author><text>URL schemes are not the most comprehensive (and likely, in my opinion) way of accomplishing this tracking. Most apps do not have any kind of URL scheme.&lt;p&gt;Here&amp;#x27;s how you do it for any app on the system, with or without a URL scheme:&lt;p&gt;1. Use sysctl to get the list of active processes.&lt;p&gt;2. Filter out all system processes&lt;p&gt;3. Upload to the server for further processing.&lt;p&gt;Combine this with a silent background refresh push notification, and you can have this run ~3 times per hour without Apple throttling you!&lt;p&gt;Source: I have shipped an iOS app for a client that does exactly this, although not Twitter.</text><parent_chain></parent_chain></comment><story><title>Twitter Is Tracking Users’ Installed Apps for Ad Targeting</title><url>http://blogs.wsj.com/digits/2014/11/26/twitter-is-tracking-users-installed-apps-for-ad-targeting/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>100k</author><text>Can any iOS developers comment on whether or not Twitter required special permission from Apple or this is simply something any iOS app can do? I&amp;#x27;v read conflicting comments online.&lt;p&gt;If it&amp;#x27;s the latter, I guess we should be thankful they bothered to tell us, because there are surely other apps that aren&amp;#x27;t.</text><parent_chain></parent_chain></comment><story><title>Twitter Is Tracking Users’ Installed Apps for Ad Targeting</title><url>http://blogs.wsj.com/digits/2014/11/26/twitter-is-tracking-users-installed-apps-for-ad-targeting/</url></story>