(CNN)At Impact your World we love to share stories of ordinary people going the extraordinary distance. Here we take a look at the five acts that tugged at our heartstrings the most -- and we revisit the people who made the difference.
5 people who impacted their world this year - and what they're up to now
The choice to become a teacher is not something you take lightly. Neither is the decision to become an organ donor.
Jodi Schmidt did both: she donated a kidney to one of her students in May.
Schmidt is a first grade teacher at Oakfield Elementary School in Wisconsin.
Natasha Fuller is a student in her class who suffered from prune belly syndrome, a rare birth defect marked by urinary problems and weak abdominal muscles.
Schmidt didn't know the extent of Fuller's problem until she stumbled upon a desperate Facebook post. The clock was ticking for the 8-year-ol and Fuller's family was pleading for a kidney.
It was then Schmidt decided she needed to help.
"I didn't think anything of it," Schmidt told CNN in September. "Then it totally just hit me, and I told myself I'm going to get tested for it."
Schmidt was a perfect match.
Now, eight months later, Fuller is an active, happy girl attending school full time.
"She has grown incredibly!" Schmidt says. "She is able to participate in all activities, eat foods that she chooses, do sleepovers, etc. She is having a blast."
The teacher's generosity has become a point of family pride.
"My middle boy became good friends with Natasha and talks often about me giving my kidney away to save Natasha's life, and my oldest daughter is so proud of my commitment to help others," Schmidt says.
"They have witnessed firsthand the love of our communities, lending a helping hand, patience during my recovery, and learned that organ donation saves lives."
When 7-year-old Ethan Engum and his mother started a GoFundme campaign to help the Green Bay, Wisconsin, Police Department replace a beloved K9, they never thought they'd start a chain reaction.
In less than 24 hours, they raised more than $500 to replace 4-year-old "Cops," a Belgian Malinois who suffered severe health problems and died in August. Within days, the amount grew to $12,000.
Capt. Kevin Warych says the department plans to buy a new K9 early next year. In the meantime, Ethan continues to visit the department's officers and dogs.
"They are my friends," Ethan says.
"We wanted to show him his hard work was paying off," says Warych. "Every time he came to the department, we arranged for him to meet and greet officers and other K9s."
Engum will have the opportunity to name the new K9, but he doesn't yet know what he'll call it.
When waiter Kasey Simmons paid for an elderly woman's groceries, all he expected in return was a smile. Instead, he got a $500 tip the next day.
Simmons was shopping in a Dallas-area grocery store in August. He was wearing his Applebee's uniform when he came across a woman who looked like she needed a pick-me-up.
"Whenever I see someone who has had a bad day, I need to let them know that it could be much worse," Simmons told CNN.
He decided to pay for the woman's groceries. It wasn't until later that he found out how much it actually meant to the lonely widow.
"Her husband of 58 years met her at a Piggly Wiggly and thought she was the most beautiful woman in the store. He bought her groceries," Simmons told CNN. "When I paid for her groceries that day, she had a flashback. It made her day so wonderful."
The next day, the woman's daughter came to Applebee's, where Simmons works as a waiter, ordered a glass of mineral water and left the massive tip.
"In my heart, I did nothing to earn $500 from that woman," he says. "It made me feel better. I changed this lady's life at least for a little bit."
As for what he did with the $500, Simmons says he "paid his phone bill with some of it and bought lottery tickets to share with other customers."
The waiter and the widow have stayed in touch.
"$17 was nothing to make a lady smile," Simmons says. "We are good friends now."
Four-year-old Norah Wood and 82-year-old Dan Peterson struck up an unlikely friendship in a grocery store.
It all started when the little girl shouted out to the older man, who looked a bit down standing in the aisle. "Hi old person! It's my birfday today."
Tara Wood, Norah's mom, took a picture of the two chatting and posted it on her Facebook page.
Someone recognized the man and sent his contact information, commenting that it was "the first time they'd seen him smile since his wife died."
That could have been the end of the story. But it was actually the beginning of a special relationship.
"Dan joined our family for Thanksgiving and we still visit him once a week," Norah's mom told CNN. "I speak with him a couple of times a week just to check in to see if he needs anything. He's getting mail and letters from people all over the world. He's never felt more loved."
Jeni Stepien-Maenner's father was murdered 10 years ago and was an organ donor. The man who received his heart is Arthur Thomas.
Stepien-Maenner stayed in touch with Thomas through the years. When she was planning her August wedding in Pittsburgh, the first person she thought of to walk her down the aisle was the man with her dad's heart.
Thomas agreed and traveled from New Jersey with his wife to the wedding.
"Tom (Arthur Thomas) and I talk a LOT, " Stepien-Maenner told CNN this month. "About two months following the wedding, it was sometimes a few times a week."
"Sometimes he's traveling, or I'm caught up with work. But we always touch base at least biweekly."
"It's convenient because we can text, email or call."
About two months ago, Stepien-Maenner and her husband began house-hunting in D.C.
"Tom was helping via text and giving us lots of advice!," she says.
"He's involved in our lives and we are so lucky that our wedding in August opened that different window of friendship for us!"
"We can't wait to all spend some more time enjoying each others' company."