It's National Donut Day! Instead of fattening up on donuts, try these donut-related apps.

National Donut Day has been around since the 1930s, and there's a serious reason behind it: It honors the men and women who served donuts to soldiers during World War I. National donut chains and mom and pop bakeries around the country are celebrating with free donuts today, but if you're on a diet or otherwise restricted, you can still get in on the fun.

Turns out there are a bunch of donut-related apps and games on the App Store. Most of these are free to download but sport some sort of in-app purchases. You might want to put some parental restrictions on your donut-crazed kids' iOS devices before letting them play these games. Not all of them are games, either. We've got utilities for donut chains and iBooks too!

1. More Donuts!

Maverick Software has a bunch of food-related apps. This one lets you make, bake and eat your own virtual donuts, complete with real-world ingredient lists.

2. Donut Maker

Crazy Cats' virtual donut making app lets you make donuts from scratch, bake 'em and decorate 'em to your heart's content.

3. Hot Donut

Roll down hills and jump in a race to the finish a la Tiny Wings. Roll, jump and dash using simple controls.

4. A Fair Food Donut Maker

Make and decorate food you might find at a carnival, including fried dough, cotton candy, and, of course, donuts.

5. Amy's Donut

Make your own donuts, choosing between 80 different fillings and 80 different toppings. More choices than Dunkin' Donuts or Tim Horton's!

6. The Simpsons: Tapped Out

Of course, no list of donut-related games and apps would be complete without The Simpsons: Tapped Out, the popular game from EA that puts you in the world of the popular cartoon characters as you build your own version of Springfield, the Simpsons' home town. Donuts play an important role in Tapped Out, serving as the premium currency that is used to purchase exclusive characters and speed up advancement.

7. Dunkin' Donuts

The official app for the popular donut chain that's a veritable institution in some parts of the United States (which the company tells us runs on its products). Top up your payment card, get deals, offers and rewards, find shops close by, and more.

8. Krispy Kreme Hot Light

Find out exactly when fresh-made donuts are coming off the line of the Krispy Kreme near you (find out when the Hot Light is on, in other words). Locate nearby Krispy Kreme shops, invite friends.

9. TimmyMe

The official Tim Horton's app. Load up your Tim Card, find a restaurant nearby, check nutritional info (or don't, unless you want to feel bad about yourself) and organize "Tim's Runs" for you and your friends and coworkers.

10. Babycakes Covers the Classics

Want to learn how to make delicious vegan, gluten-free desserts including donuts and snickerdoodles? Babycakes' iBook has you covered.

11. The Donut: History, Recipes and Lore

Michael Krondi examines the history of the donut and collects recipes from around the world. Gorgeous photography will get your mouth watering.

12. Your favorites?

What indispensable donut-related games and apps are missing from this list? Let me know in the comments!