Yahoo remains on its small-company acquisition roll. The search engine prince has acquired a to-do list app called Astrid. Financial terms of the deal were not disclosed.

Astrid is available for Android phones and tablets, iPhones and iPads and the Web, and lets you create lists anywhere and sync them across all devices with free cloud Relevant Products/Services backup Relevant Products/Services. Astrid also lets you set up reminders, share lists with other people, and add tasks on the go with voice recognition.

"We are grateful to the more than 4 million of you who have downloaded our apps, to those who have shared Astrid with friends, family and co-workers, and to all who encouraged us with your kind words along the way," wrote Jon Paris, co-founder along with Tim Su, of Astrid.

The Daily Habits Focus

Astrid launched with a goal to help more than 1 billion people be happier, healthier and more productive. The product will continue to work "as is" for the next 90 days but will not accept new premium subscriptions. It's not yet clear exactly how Yahoo will integrate the app into its bigger software Relevant Products/Services picture.

"We're excited to welcome Astrid to Yahoo's mobile Relevant Products/Services team," Yahoo said in a statement confirming the deal. "Their background in personalized mobile experiences is impressive, and we know they will be a huge asset to as we continue to re-imagine our products."

Greg Sterling, principal analyst at Sterling Market Intelligence, told us the to-do app Astrid is another "daily habits" acquisition for Yahoo, although it's not clear what form the app's functionality will take as it's incorporated into Yahoo.

"CEO Marissa Mayer is very -- and wisely -- focused on upgrading Yahoo's mobile user experiences," Sterling said. "And all the acquisitions of late have been focused on mobile development talent, or technology in several of the cases."

And speaking of talent, the Astrid team, which is in the neighborhood of eight to 12 people, will also join Yahoo.

Summing It Up

Just more than a month ago, Yahoo acquired Summly, which offers an algorithm that generates summaries from hundreds of news sources, in a deal the AllThingsD blog pegged at $30 million. A so-called "daily habit" app, Summly was free and was available for the iPhone. The app automatically determined the most relevant facts in a story and generated short summaries that helped the reader quickly grasp the main points from diverse news sources, from The Wall Street Journal to ESPN. To read the full story, readers then would click through to the original article.

Also in March, Yahoo bought Jybe, another daily habit technology. Jybe is a personalized recommendation company founded with the vision to help people find the things they love to do based on what's trending in social circles. The Jybe app is now closed, but Yahoo's senior vice president of the Cloud Platform Group said "we're confident that their data Relevant Products/Services- and science-driven experience will supercharge our efforts to build great products and experiences for the millions of people who come to Yahoo every day."