On-device · Local alerts · No accounts

Watch the websites
you depend on.

NetSweep is a personal security watchtower for iPhone and iPad. Pin the sites you care about — your bank, your email, your domain — and the app silently re-checks their TLS chain, security headers, DNS, and CVE exposure. Local alerts fire before anything breaks. Nothing leaves your device but a normal browser-style request to the hosts you pinned.

Download on theApp Store See how people use it →
Why a watchtower

Certs expire on a Tuesday
and no one tells you.

The internet runs on certificates that quietly age out. Headers get weakened. CVEs land. DNS gets repointed. NetSweep watches the surfaces you care about and surfaces only what changed — so you don't have to remember to check.

Per-host deep inspection

TLS chain, OCSP revocation, DNS records, HTTP→HTTPS redirect, six security headers, HSTS preload eligibility, Certificate Transparency log entries, and matching CVEs — one polished report per host.

Background re-checks

iOS wakes NetSweep periodically to re-probe every pinned host. Cert renewed? Expiring soon? Fingerprint changed? Headers weakened? You get a local notification — no backend, no account.

What's new at a glance

Open the app and only the deltas surface: cert renewed, fingerprint rotation, expiring in 7 days, 3 new CVE matches. A morning brief for the digital infrastructure you trust.

Spatial map of trust

Your device at the center, every pinned site orbiting around it — tinted by health, draggable, pinch to zoom. The constellation pulses softly and recolors when something needs your attention.

Tags + Health dashboard

Tag your sites (Work, Personal, Family) and filter the meta-view. Stat tiles tap to drill in — see only the broken, only the expiring, only the watched.

Portable watchlist

Export your pinned sites as a tidy JSON file. Restore on a new device, share a starter list with a coworker, or just keep a backup. Tags ride along.

What gets checked

One tap. Eight signals.

Every inspection runs the full battery and writes the result. The Watchtower repeats it on its own schedule and tells you only what changed.

01

TLS handshake

Negotiated protocol version, full certificate chain, leaf expiry countdown, handshake time. Old TLS or weak chains flagged.

02

OCSP revocation

Asks the issuing CA whether the cert has been retracted. A revoked cert is a stronger signal than an expired one.

03

DNS records

A / AAAA resolution with primary address tracking — a silent re-point gets surfaced as a "primary DNS address changed" alert.

04

HTTP→HTTPS redirect

Confirms plain-http traffic gets redirected to https. A missing redirect is a real-world security finding for non-HSTS sites.

05

Six security headers

HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy — scored 0–100 with a present-count badge.

06

HSTS preload eligibility

Checks max-age, includeSubDomains, and the preload directive against the hstspreload.org criteria so you can apply with confidence.

07

Certificate Transparency

Pulls recent CT log entries from the public crt.sh API. Surfaces unexpected issuers, sister certs, or unknown subdomains.

08

CVE matches

Auto-searches NIST's public NVD catalog by apex domain. Read-only links to the public records — never any exploit detail.

The watchtower

Pin. Re-check. Alert.

A simple, repeatable loop. Add a site, the app does the rest.

01 / PIN

Pin a site

Type or share a URL into NetSweep. The Inspector runs the full battery and you get a polished report. Tap "Watch" to add it to the watchtower.

02 / RE-CHECK

iOS wakes us up

A background app refresh task re-runs every watched site every ~12 hours, capped to four concurrent probes so your battery doesn't notice.

03 / ALERT

Only the deltas

The "What's New" panel surfaces every change at a glance. Local notifications fire 30 / 14 / 7 / 1 days before a cert expires.

Last refresh · 6 hosts re-checked
github.comcert renewed (now 84 days valid)
cloudflare.comunchanged · TLS 1.3 · 312d
apple.comunchanged · TLS 1.3 · 187d
yourdomain.comexpires in 12 days
mozilla.org3 new CVE matches
wikipedia.orgTLS fingerprint changed
The toolkit

Six instruments,
each doing one job well.

No filler. Every tool serves the watchtower mission.

Inspect Site
TLS · DNS · headers · CVE
Health
every watched site
Timeline
changes + lookups
CVE Search
public NVD lookup
Connection
your link state
Settings
watchtower + alerts
Built privacy-first

Everything runs on your device.

No accounts. No analytics. No ads. Your watchlist never leaves your device. Outbound requests are the same ones a normal browser makes to the hosts you pinned — plus three optional public lookups (public IP, NVD, crt.sh) that send your query, never your data.

0
Accounts required
0
Trackers or ads
100%
Local notifications
LAN scanning
Common questions

The five things people
ask first.

Does NetSweep scan my local network?

No. NetSweep never scans any device on your LAN. It does not request the iOS Local Network permission and does not declare any Bonjour service types. It only inspects the public hosts you choose to pin.

Do I need an account?

No. NetSweep has no accounts and no servers. Your watchlist, every inspection result, and every detected change are stored in SwiftData on your device only.

How do the expiry alerts work?

NetSweep schedules local notifications on your device 30, 14, 7, and 1 days before a watched certificate stops being valid. They are computed from data already on your device and delivered by iOS's UserNotifications framework — no remote push service is involved. Tap the alert and the Inspector opens pre-loaded with the affected host.

What does an inspection actually check?

Each inspection runs the full battery: TLS handshake (chain + protocol), OCSP revocation, DNS A/AAAA, HTTP-to-HTTPS redirect, six HTTP security headers (HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy), HSTS preload eligibility, Certificate Transparency log lookup, and a CVE search against NIST's NVD by apex domain.

Is NetSweep free?

Yes. There are no in-app purchases, no subscriptions, and no ads. NetSweep is a portfolio piece — built to be a useful, polished tool people actually keep on their phone.

A portfolio piece

Designed and built by Cam Garrison.

NetSweep is a showcase of full-stack iOS craft: a custom SwiftUI spatial canvas with UIKit-backed gestures, a concurrent on-device security probe engine (TLS handshake capture, OCSP via SecTrust, raw NWConnection HTTP probe, CT log lookup, NVD search), SwiftData persistence with delta detection, BGAppRefreshTask background watching, App Intents for Siri integration, and Apple-grade accessibility from Dynamic Type to Reduce Motion.

Engineering highlights
InterfaceSwiftUI · UIKit gestures
Probesasync/await · TaskGroup (cap 4)
TLSsec_protocol verify block
OCSPSecPolicyCreateRevocation
BackgroundBGAppRefreshTask
PersistenceSwiftData · @Predicate
IntegrationApp Intents · URL scheme
AccessibilityDynamic Type · Reduce Motion
Available now on iPhone & iPad

Start watching the sites you depend on.

Free. No accounts, no ads, no tracking. Pin a few sites and NetSweep takes it from there — you only hear from it when something changes.

Requires iOS 18 or later.