This app was mentioned in 4 comments, with an average of 2.75 upvotes
There's gotta be an app that will mirror-flip your phone's screen for this purpose, surely.
*quickly googles* Hmm. Well, there's SpeedView for Android, which has GPS based HUD functionality, but I'm not sure if it supports any of your phone's other features you may want to be using simultaneously.
If you have an Android device:
Test it out at different increments. If you can mount it on your bars then do that, hit 30mph, then 50mph, then 70mph, 90mph just keep it consistent so you can see what percentage your speedo is off.
Oh okay. I'm extremely sorry, if i sounded like I was rude. I didn't completely understand what you meant, however after Winston-Green explained it a bit I get the gist of it.
So if I was to install this application and compare it to the speed registered on my car, you would say that the reading from the app is more accurate?
My question is, if the reading on the app is more accurate, if I was caught on the camera, would you say that camera would pick up the speed that the app does or what the car reads?
I am extremely sorry if I sounded rude, didn't mean it at all. Thank you very much for your advice though. I'll try to get a reading done this week.
Get Speedview and mount to your dash, I've found it very accurate and drive with it. https://play.google.com/store/apps/details?id=com.codesector.speedview.free