Privacy Policy.

Your access code

When you enter an access code, the app sends it to my server to unlock the app. After that it checks about once a day, when it has a connection, that the code is still good.

What is recorded

• The code, which app redeemed it, and whether the device runs iOS or Android.
• A random identifier the app makes up on your device, so a code cannot be used on more devices than it was sold for.
• When the code was redeemed, when it was last checked, and when the license runs out.

That identifier is not your device's serial number and it is not an advertising identifier. The app makes it up, it means nothing outside this app, and only a one-way hash of it ever leaves your device. On Android, uninstalling the app erases it. On iPhone and iPad it stays on that device, so a reinstall gets the same seat back.

I know which organization each code was issued to. I do not know who is holding it unless that organization tells me. Whoever handed you the code may keep their own list of who got which one.

Signing out, in the app's Settings, gives the seat back and stops the checks.

Class sessions

A class session starts when an instructor opens one and gives you a join code. You join by entering that code and a nickname.

What is recorded

• The nickname you typed. Pick something your instructor will recognize.
• Which labs you were assigned, and which ones you opened, finished, skipped or were helped through.
• Each Check Work you get wrong, each blown fuse and each hazard: what happened, what it cost you, and the wiring at that moment.
• Your score.
• A raised hand.
• In a live class, each time you leave the app while work is assigned, and for how long, to deter cheating during tests.
• Whether your device runs iOS or Android, and the time each of these things happened.
• On an Enterprise seat, which access code did the work.

What your instructor sees

In a live class, while a lab is assigned and open, your instructor's board shows the wiring on your screen as you work, along with everything in the list above. The live wiring is passed straight through to the board and is not stored. While no work is assigned, the board shows only that you have joined the class.

In a homework session, the board shows which labs you have done, the Check Work attempts you got wrong and your blown fuses. It does not show the wiring on your screen, and leaving the app is not tracked.

What is not recorded

• No real name, email address, phone number or account. There is nothing to sign up for.
• No location of any kind.
• No advertising identifier (no IDFA on iOS, no advertising ID on Android), and nothing derived from your hardware.
• No contacts, photos, camera or microphone. The app never asks for them.
• Nothing you do outside a session. The labs you practice on your own stay on your device.

How long it is kept

• Your nickname is erased from my server the moment your instructor ends the class. A class nobody ends closes by itself: a live class after 24 hours with no activity, a homework session 7 days after its last activity or its due time, and never later than 30 days after it was opened.
  Nicknames are stored locally on the instructor's device until they delete that session's history. The instructor can export these results for their records.
• The rest of the class record, which is the list above without the nickname, stays on my server. On an Enterprise seat it stays tied to the access code that did the work, and your instructor can see which code that was. I keep it to fix problems and to answer questions from the organization that licensed the seats about its own classes. This is essentially anonymous test data.
• Your instructor's device keeps the class results with your nickname until they clear the log or sign out. Anything they export is a file they handle under your school's or employer's rules.
• Your own device keeps your progress through the assigned work and erases it when the class ends.

Who can see it

• Your instructor, and any other instructor in that class.
• Me, when I am fixing a problem or answering a question from the organization that licensed the seats.
• The company that hosts my server, described below, which stores the data for me and does nothing else with it.

That is the whole list. I don't sell any of it, I don't share it with anyone else, and nothing in the app is used for advertising or to follow you across other apps and websites.

Where it goes

The server is a database I run with a hosting company, in the United States. Everything the app sends travels over an encrypted connection.

The database is closed to the outside. The app cannot read or write it directly: every request goes through server code that checks the access code or the class it belongs to. The hosting company handles the data only on my instructions, and its data processing terms hold it accountable for keeping the data secure and confidential, which is the same protection this page promises.

Like anything on the internet, the server sees the IP address a request comes from. I use it for one thing: slowing down anyone who tries to overload the server. For that I keep only a one-way hash that changes every day, and old ones are swept out. My host's own request logs also hold it for a short time.

If you are an instructor

An instructor seat is an access code like any other, so everything under "Your access code" applies to you. The classes you open are recorded against that code: when each one opened and closed, what you assigned, and the results.

Your board keeps a log of your classes on your device, nicknames included, so you can look back at results and export them later. Clear the log, or sign out, and the nicknames are gone. An export is a file you send wherever you choose. From the moment of export it is your organization's record, not mine.

Your choices

• You can leave a session from its screen. Work you already turned in stays with your instructor.
• Signing out gives your seat back and stops the daily check.
• If you want the class records tied to your access code deleted from my server, email me the code and I will delete them. A record that was never tied to a code can't be traced to anyone once its nickname is erased, including by me.
• If you email me, or send feedback from inside the app, I get the email address you send the message from and whatever you wrote, and I use them to answer you. The app adds its version, your device model and your operating system version to a feedback draft so I can reproduce the problem. You can delete those lines before you send the message.

XFMR Lab Enterprise is built for apprentices and working linemen. It is not meant for children under 13, and I do not knowingly collect anything from them.

If this policy changes, the new version goes on this page with a new date.

This page covers XFMR Lab Enterprise, and any class session you join from XFMR Lab. Outside a class session, XFMR Lab and Lineman's Reference: URD collect nothing; their policy is at linemanapps.com/privacy. Lineman's Calculator has its own at linemanapps.com/calculator/privacy.