Knightify Pulse VS Diffee

Knightify Pulse's answer

Pulse reads the signals an Apple Watch already collects (sleep, resting heart rate, HRV, movement, recovery), compares them only against the wearer's own rolling baseline, and turns the result into a single human sentence for their partner, such as "A calm evening might mean a lot today." It never shows a number, a chart or a verdict, and the raw health data never leaves the wearer's phone — there is no cloud AI and no third-party analytics in the loop. Cues also expire at midnight, so there is no archive of anyone's wellness to scroll back through.

Knightify Pulse's answer

Most of Pulse's neighbors are either fitness trackers (WHOOP, ŌURA Ring, Fitbit) that report your own numbers back to you, or general couple apps (Couple.me, Between, Happy Couple) built around messaging and shared calendars. Pulse sits in between: it actually connects to your Apple Watch data, but instead of handing your partner your heart rate or sleep score, it converts that into one caring sentence and a couple of suggestions, with the raw numbers enforced — in code, not just policy — to never leave your phone. It also has no history view, no cloud AI, no ads and no data sold, so there's nothing to be surveilled or profiled. For a couple that wants a partner to say "go easy on me tonight" without oversharing their biometrics, Pulse does that in a way a generic tracker or chat app doesn't.

Knightify Pulse's answer

Pulse is built for couples who own an iPhone, and ideally an Apple Watch, and who want a gentler way to stay attuned to each other day to day, particularly when schedules, distance or ordinary bad days make it hard for one partner to explain what's going on. It's aimed at privacy-conscious users: people who like the idea of a partner-aware app but would never want their own heart rate, sleep or cycle data actually leaving their phone. It's currently iOS/watchOS only, shipped in English and German, and free for both partners in the relationship.

Knightify Pulse's answer

Couples rarely fail on the big, dramatic days; they erode on ordinary ones, where one partner is quietly depleted, the other reads it as distance, and neither has the energy left to open the conversation that would fix it. The team at Knightify FlexCo, a small studio in Vienna, noticed that an Apple Watch has been measuring the raw ingredients of that gap all along, sleep debt, resting heart rate, HRV, movement, without anyone turning it into something a partner could actually act on, and without it becoming surveillance. Pulse was built around three refusals: no numbers ever cross between partners, no archive of another person's body, and no verdict, only an opening. Every cue is a single human sentence, deleted at midnight, sourced to real health references, and enforced in code rather than policy.

Knightify Pulse's answer

Pulse is a native iOS and watchOS app. It reads Apple HealthKit data (sleep, resting heart rate, HRV, movement, respiratory rate, blood oxygen) with read-only, versioned consent, and builds each person's rolling baseline and cue entirely on-device, with deterministic rule-based scoring rather than any large language model or cloud AI service. Chat, photos and the daily question use CryptoKit with AES-GCM for message content and Curve25519 for key agreement, with the private key held only in the user's iCloud Keychain. A self-hosted WebSocket relay on Knightify's own infrastructure carries already-encrypted chat traffic and typing/read-receipt signals; it is not a third party and stores nothing. There are no analytics, ad or tracking SDKs anywhere in the app.