About
Lock Solid
A practice dial for the three-number combination lock on a school locker — for a kid who is about to meet one for the first time and would rather not find out in a crowded hallway.
What it is
A dial you spin with your finger, on a phone. It teaches the sequence a real lock needs: three full turns right to the first number, back to the left past it to the second, then right to the third.
The free lesson is five rounds long and the help fades as it goes. Round one gives you arrows, a turn counter, a lit target and a line of coaching. Round five gives you three numbers on a paper slip and nothing else, which is the situation on the first morning of school.
What it teaches, and what it does not
It teaches a standard rotary combination dial -- the kind built into a locker door or hanging off it as a padlock, with numbers printed around the face and three numbers to dial in order. Dials up to 0–59 are supported; the app works out how many numbers your lock has from the combination you type in.
It does not teach:
- Keypad or push-button locks.
- Key locks.
- ADA lever locks
If your child has been issued something other than a rotary dial, this is not the right tool and you should not pay for it. The five free rounds will show you which you have within about a minute.
What it does with your child's data
Nothing leaves the device. There is no account, no sign-in, and no email address needed to use it.
- The locker color, how far through the lesson you are, and the combination you type in are stored in your browser on your own phone. They are never sent anywhere.
- No advertising, tracking scripts, or third-party analytics.
- No information is collected about the user.
- If you buy the paid unlock, payment is handled entirely by Stripe. Card details never reach this site.
Clearing your browser data will reset progress, and on iPhones Safari clears it by itself after about a week of not visiting. That is why a purchase comes with a recovery code. Keep the receipt email and you can get access back.
What it costs
- Free: the whole five-round lesson, with a sample combination.
- $3.99, once: practice your child's own combination as much as you like, plus a harder ladder that takes away the help and then the numbers themselves.
For schools
You are welcome to link it from a resource list, a transition packet, or a welcome email. The free lesson is the whole instructional experience, so a family never has to spend anything for it to be useful.
If cost is an obstacle for a family, please reach out.
Who made it
One parent, for one nervous kid, before their first day of middle school.
Questions, problems, or a school that wants a free-access link: locksolid@code0interactive.com.