There is probably a thread about this somewhere but I don’t see it. Stanford, the Ivy League, and other schools have created an on-line application called the Coalition Application. It is intended for students starting in ninth grade to create a portfolio of work and accomplishments. It could be a good method to collect all your college worthy efforts into one place.
The actual application is intended to start going on-line this month to apply for 2017. I would recommend juniors not use it only because there will always be bugs in new software. After this year it should be fine and there will be plenty of feedback on it.