When Heidi and Chris are travelling in his truck to the hotel to take a look around Heidi's side of the truck is travelling much faster than Chris's.
When Heidi first arrives in town, she's looking up at the store front signs and there's one for Whisperwood & Co. next to a bakery called the Bun Basket. Later in the movie, the store front sign next to the bakery says "Erica's" and it's the shop owned by Heidi's friend Erica.
When Tom comes to Chris's classroom to discuss the dance preparations we see an American flag with fifteen stars hanging vertically on the classroom wall. This historical version of the flag is called the "Star Spangled Banner" flag as this version flew over Fort McHenry in Baltimore Harbor during the naval portion of the Battle of Baltimore during the War of 1812. Seeing the flag during the battle inspired Francis Scott Key to write the poem that became America's national anthem. Thus this is an appropriate flag for the history classroom. However the flag is hanging vertically with the blue field of stars to the right. The US flag code states the blue field must always be to the upper left. A history teacher would know this.
Megan's messages on Heidi's phone appear green, but both have iPhones.