Add iOS and Android code examples for cross-platform user identification

[camerondeleone]

Add example DeepLinkIdentityManager implementations showing how to handle deep link handoffs from web to mobile apps, with proper identify/alias calls to merge user activity across platforms.

Changes

Please describe.

Add screenshots or screen recordings for visual / UI-focused changes.

Checklist

• Words are spelled using American English
• PostHog product names are in title case. It's "Product Analytics" not "Product analytics". If talking about a category of product, use sentence case e.g. "There are a lot of product analytics tools, but PostHog's Product Analytics is the best"
• Titles are in sentence case
• Feature names are in sentence case. It's "Click here to create a trend insight" not "... create a Trend Insight" and so on.
• Use relative URLs for internal links
• If I moved a page, I added a redirect in vercel.json
• Remove this template if you're not going to fill it out!

Article checklist

• I've added (at least) 3-5 internal links to this new article
• I've added keywords for this page to the rank tracker in Ahrefs
• I've checked the preview build of the article
• The date on the article is today's date
• I've added this to the relevant "Tutorials and guides" docs page (if applicable)

[vercel]

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Project	Deployment	Review	Updated (UTC)
posthog	Ready	Preview	Jan 22, 2026 5:58pm

[marandaneto]

should this be within the normal path only? L52
otherwise if identifiedViaDeepLink is true, its gonna be false again right away, is that intentional?