I switched phones — how does my subscription continue? – whoisthis

Same platform (iPhone→iPhone, Android→Android): sign into the same Apple ID / Google account on the new phone and tap Restore Purchases.
iPhone → Android (or Android → iPhone): the old subscription stays tied to the old store. Cancel it in the old store first (Apple: https://apps.apple.com/account/subscriptions · Google: https://play.google.com/store/account/subscriptions), then subscribe again from the new phone. For any remaining paid time on the old platform, contact info@whoisthis.io and we'll help.