The magic-number method, drilled until it sticks.

Random exam-style subnetting questions. Step-by-step reveals. A cheat sheet one tap away. Built for the CCNA and Network+ candidate who wants to solve any subnet in seconds.

iPhone · iPad · Mac · Free
Download on the App Store
How it works

Practice until your fingers
know the method.

Slash drills the magic-number method with random questions until you can solve any subnet in seconds. Wrong answers teach. Right answers build confidence. The cheat sheet is always one tap away.

?

Random exam-style questions

Find the network, broadcast, first or last usable host. Mixed text-input and multiple-choice — both modes mirror the CCNA exam format.

↓

Step-by-step reveals

Get it wrong and Slash walks the magic-number method for that question, shows the full subnet, and gives you a "Quick Way" shortcut.

▦

Cheat sheet, one tap away

The magic-box grid — the same 8-column row you'd scribble on the laminated sheet at Pearson VUE. Accessible from any question via the table icon.

💡

Hint button

Surfaces the magic number for the current question with a link to the full cheat sheet. A nudge, not the answer.

◎

Progress and milestones

Track total accuracy and per-question-type performance. Earn the "You're Ready" badge at 50 correct with 90% accuracy. No streak guilt, no daily nag.

∅

Zero network calls

Fully offline. No accounts, no telemetry, no third-party SDKs. Not now, not ever. Verify with Airplane Mode.

Free · Universal Purchase

iPhone. iPad. Mac.

One download, every Apple platform. Each gets a real native build — keyboard accessory on iPhone, hardware-keyboard friendly on iPad, menu bar and float-on-top on Mac. The calculator tab is still there for ad-hoc lookups.

Slash running natively on macOS showing a subnet result window
A short list

Things Slash will never do.

Privacy isn't a feature. It's the default.

  • ✓ No accounts, no sign-in
  • ✓ No network requests of any kind
  • ✓ No analytics, crash reporting, or telemetry
  • ✓ No advertising or advertising identifiers
  • ✓ No third-party SDKs
  • ✓ No location, contacts, photos, or device IDs
Who made it

One indie developer.
One real native app.

Built by a CCNA who passed using this exact method. Slash is one focused thing: the magic-number method, drilled until your fingers know it, with native iOS polish and a cheat sheet you can write at the testing center.

Learn

The math behind the method.

Every CCNA candidate relearns subnetting from scratch at least once. We wrote a short visual guide to the magic-number method — the same model Slash is built on.

Subnet math for engineers who keep forgetting it →

Get Slash free on the App Store.

Free. Universal Purchase across iPhone, iPad, and Mac.

Download on the App Store

Support

Questions, feature requests, or bug reports? Reach out anytime:

tyler.dix@gmail.com

★ Rate Slash on the App Store →

Privacy Policy

Effective date: May 5, 2026

Slash collects nothing. The app runs entirely on your device with no network connection, no account, and no third parties.

Data We Collect

None. Slash does not collect, store, or transmit any personal information.

What Stays On Your Device

This data never leaves your device. If you delete the app, it's gone.

What We Do Not Do

Children's Privacy

Slash does not collect personal information from anyone, including children. The app is rated 4+ and is safe for all ages.

Changes

If this policy changes, the updated version will be posted here with a new effective date.

Contact

Questions about this policy? Email tyler.dix@gmail.com.