RetiredBA/BY
It should be easier to implement these days.
In fact, I think a smartphone app would be quite possible for many phones that have good accelerometer sensors.
You only need 3 parameters. Takeoff length, end speed, and a start time/button. Length determines average G's needed over a certain time period. If too much of a deficit is accumulated by a predetermined time on the way to V2, then an alert is issued.
To whomever decides to make this app... I'll PM you my bank info for my 10% royalty cut.
