Lumo Runs Note Search On-Device on iOS to Cut Latency and Keep Data Private

Lumo, a memory copilot app for iOS, is designed to process notes locally rather than relying on cloud servers, which its developers say avoids network delays and keeps sensitive content off third-party systems. The app pre-warms the audio session so recording begins within about 100 milliseconds of tapping the microphone, and it scrubs filler words and ambient noise with native audio filters. Text embeddings are generated on Apple Silicon's Neural Engine, with token processing overhead said to stay under 15 milliseconds. Notes and their vectors are stored in an encrypted SQLite index protected by Apple's Data Protection Keychain keys. The developers argue that each extra half-second of friction in capture sharply reduces how often users actually record notes, which motivated the fast, minimal-step design.