Microsoft plans to make a calendaring app for Windows Phone 7 based on the suggestion of a 26-year-old single mom of four young kids who gets US$5,000 and a phone for coming up with the winning idea.

Microsoft ran a contest in June inviting anyone to submit an idea for a Windows Phone app. A "Windows panel of judges" chose the grand prize winner from among the top 150 entries with the most votes.

The grand prize winner, whose name is listed on the contest website as Emili, gets a Windows Phone 7 phone and $5,000. The app she proposed will be available to her and anyone else as a free download in the Windows Phone 7 marketplace.

The app she pitched is called "one tap organizes everything" and has two components, including an agenda designed to be easily read at a glance and a meal planner.

In her lengthy description of the app, Emili wrote that she'd like to be able to color code a category of events in the agenda for each of her kids. For example, one category would be for appointments related to her daughter Abbey, and events in that category would show up as a green dot on the agenda. Clicking on the dot would open details of the appointment. "This way at a glance I can see that Abby has to stay home from school for her appointment and I avoid keeping the wrong kid home from school because I forgot who's appointment it was. (and YES I have done that!!! lol)," she wrote.

Users would also be able to set alarms for each appointment, customizing them by tone and with a snooze feature.

The second part of the app would be a meal planner that would let users plan meals daily, weekly or monthly. It would feature recipes, a shopping list and a calculator. A meal planner tab would appear in the agenda and clicking on it would display the meal planned for that day. Users would be able to look at recipes in the app and add items from the ingredients list to their shopping list or add all ingredients from recipes in any given day, week or month to the shopping list.

When Microsoft ran the contest in June, it said it would aim to complete and offer the winning app free by the end of the year. The company does not have an estimated availability date and declined to assist with an interview with Emili. Emili did not respond to an e-mail request for comment.

Her app ranked 35th by number of votes. It had 306 votes compared to 1,802 for the most popular idea. That proposal was for an app that would let users access their Windows Media PC from their phones.

In addition to the grand prize, Microsoft named four runners-up who each won a 16GB Zune HD. Their proposals include two ideas for applications for managing shopping lists and recipes, a GPS mapping app and an app to help manage medication.

On Thursday, Microsoft said it had reached 777 apps in its Windows Phone 7 app store. The phones have begun selling in some regions of the world and hit shelves in the US in November.