For users and their IT departments

Your data stays yours.
We built it that way.

Both tools are offline-first because switchrooms have no signal. That design choice has a side effect worth spelling out: they are also about as private as working software can be. This page is the plain-English version, with enough technical detail underneath that your IT department can verify it rather than take our word for it.

What we hold One record per licence: the name you gave us and a 16-character device code. Nothing else.
What we see of your sites Nothing. Surveys, diagrams and schedules live on your device. There is no server side, so no copy exists anywhere we can reach.
How you can check The Android app holds one permission (internet), used only when you tap "Check for updates" or, on admin licences, "Download library" in the Relay Wiring reference; neither request carries any identifiers. Verify with standard tools; commands below.

The whole of what we hold

When you request a licence, you email us two things: the name you typed into the app and the device code it shows you. We keep that pair so we can sign your licence key, and re-issue it if you change handsets. That is the entire dataset. You send it yourself, from your own mail app, and you can read exactly what's in it before it goes.

  • No accounts, no passwords, no profile.
  • No usage tracking, no analytics, no crash reporting, no advertising IDs.
  • No payment details stored in or around the software; invoicing happens by email like any other supplier.

Want your licence record deleted? Email us and it's gone. Your installed licence keeps working; it lives on your device, not with us.

What the device code is (and isn't)

The 16-character code on the licence screen is a one-way SHA-256 hash computed on your handset from the app's installation identifier, the phone's model fields and your name. It is not your IMEI, serial number or phone number, and none of those can be recovered from it.

On Android 8 and later the underlying identifier is scoped to the app's signing key: other apps on the same phone are given different values, so the code can't be used to correlate you across apps. It identifies your copy of BTS Toolbox on that handset, which is exactly as much as a per-device licence needs, and nothing more.

Your sites never leave your device

BTS Toolbox does everything on the phone. Relay settings, test results and selections are stored locally and computed locally. The only network requests in the app are ones you trigger yourself: the update check and, for admin licences only, a one-off download of the relay wiring reference library (manual drawings and terminal tables, fetched from toolbox.btspower.co.uk and kept on the phone). None of your data is in either; see the permissions note below.

SLD Platform keeps your surveys, single-line diagrams, asset registers and switching schedules in your browser's storage on your machine. There are no user accounts, no cloud store and no sync service. When you share a site file, the app hands you a file and you choose how to send it; it never routes through us.

Your network drawings are commercially and operationally sensitive documents. We treat them the simplest way possible: we never have them. They are your property, on your hardware, full stop.

For IT: verify it, don't trust it

BTS Toolbox (Android APK)

The manifest requests one permission: internet. Not storage, not camera, not location. It exists for two user-triggered features. The "Check for updates" button on the home screen fetches our public release manifest (read it yourself: btspower.co.uk/toolbox-version.json) with a plain GET carrying no identifiers, compares version numbers on the device, and hands any download to your browser. On admin licences only, a "Download library" button in the Relay Wiring reference fetches a set of public manual excerpts (terminal tables and drawings) from toolbox.btspower.co.uk with the same plain GET and stores them on the phone; ordinary licences never see that screen. There is no automatic, scheduled or startup checking; if you never tap either button, the app never touches the network. Confirm with aapt dump permissions bts-toolbox-1.15.0.apk: you'll see android.permission.INTERNET plus the app's own DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION, a housekeeping marker the AndroidX build tooling generates inside every modern app, and nothing else. Check the signature with apksigner verify --print-certs. The SHA-256 of every release is published next to its download link.

Licensing is offline public-key cryptography. The APK embeds only an ECDSA P-256 public key; your licence is a signed token verified on the device. There is no activation server, no periodic check-in, no network dependency. Android backup of app data is disabled (allowBackup=false) so licence state can't be silently cloned off the handset.

BTS Toolbox (web app, toolbox.btspower.co.uk)

Same tools, delivered as a static web app for iPhone, iPad and desktop browsers. Your browser downloads the app itself from our host and that is the only traffic: no API calls, no server endpoints, no analytics. A standard service worker caches it so it runs offline once loaded. Admin licences can open a Relay Wiring reference whose drawings and terminal tables are fetched from the same host on first view and cached the same way; still plain file downloads, still nothing sent.

The device code is a random install identifier generated in your browser and kept in its local storage alongside the name you enter and your licence key. Nothing leaves the browser: the key is verified locally with WebCrypto against the same embedded public key as the Android app. Clearing the site's data removes all of it (and produces a new device code, so you'd need a fresh key).

SLD Platform (web app)

It's a static application. Your browser downloads the app itself from our host, and that is the only traffic there is: the app's code contains no API calls and there are no server endpoints to receive data. Watch the network tab while you work; after the app loads, it goes quiet.

Site data lives in the browser's local storage under your own user profile, which is why it works with no signal. A standard service worker caches the app for offline use. Licence unlock codes are verified locally with WebCrypto, the same offline design as the Android app.

This website

Static pages on a CDN. No analytics, no tracking scripts, no cookies. The only channel between you and us is email.

Questions we haven't covered? Put your IT department in touch directly at info@btspower.co.uk. It's software built by engineers who sit on the other side of those security reviews too; it's usually a short conversation.

The short version

We hold one licence record. Everything else stays on your device, and the software is built so that you can prove that, not just read it here.

Back to BTS Power