Arc Signal LLC builds privacy and security tools that help you understand the signals around you.
Meet Pretlow Stevenson III, Arc Signal’s founder and sole developer, and read the story behind Spectra.
Our app, Spectra, brings nearby Bluetooth observations, advertised services on your joined local network, and iPhone magnetic-field measurements into one place. Use it to investigate unfamiliar surroundings, understand nearby device activity, and make better-informed decisions.
Clarity without false certainty
A signal is a clue, not proof of a hidden device or active recording. Spectra explains the evidence behind a finding and the limits of each measurement. A quiet scan cannot prove that a space is safe.
Your observations stay under your control
Scan results are stored locally. Spectra does not upload captures to Arc Signal or a remote identification service. You decide whether to export a report or share information with support. The optional Apple Watch collector is experimental and transfers captures to your paired iPhone for review.
Built to keep getting better
We regularly improve Spectra’s device catalog and detection engine to help you make better sense of nearby signals. These improvements are included in App Store updates at no additional charge. There is no separate catalog purchase or subscription.
Install the latest app update to use newer recognition. You can also recheck eligible saved sessions without changing the original. Updates do not guarantee a match or make every device detectable.
Explore Spectra
Need help?
Email support@arcsignal.dev. Start with your app version, the steps you took, and what you expected to happen. Please do not send private scan data unless you deliberately choose to share it.
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