So, if you're here you probably found my Reddit Bot, /u/TheWallGrows.
What it does, is it searches for specific phrases and once it finds a match, it will add 10 to the total height of the wall, and output it. It was built in about 2 hours with Python and PRAW.

Phrases it accepts (not case-sensitive):
grow thy wall
we need to build a wall
10 feet higher
make mexico pay for it
ten feet higher
10ft higher
ten ft higher
10. feet. higher!
10 feet taller
ten feet taller
10ft taller
ten ft taller
10. feet. taller!

Subreddits it searches:
ALL OF THEM

If you have any questions, please message me at /u/TonySesek556. :)
Have fun wall building!