For entrepreneurs, time is the most constrained resource.

Your "weekend" mornings probably go a lot like mine. For example, last Sunday I commissioned a logo. Sent a mass email. Reviewed a speech. Developed a list of prospects for a client. Approved two articles. Got on a plane. Entrepreneurs are constantly looking for the latest apps to make more of their limited attention. Here are some of the productivity apps that I and some of my entrepreneur friends are enjoying right now.

Used right, these can take your time and increase your outcome by a factor of 10 or more:

That Sunday morning's logo was dealt with by 99designs. A cup of coffee later, I had 13 new designs, five of them usable with modest tweaks. Over the week, a total of 54 options came in, for $377.

Xero booted QuickBooks at my company--and that's a timesaver in itself. Xero is native accounting in the cloud. It gives me a financial dashboard even on my mobile phone. I can project if I can afford that next hire in about three minutes using actuals. I love it.

Do customers try to reach your company by phone? Then you need this! Call tracking and recoding is a missing link for many growing companies. It was for mine. With this affordable tool, you'll know not just who is calling, but also which web search or page the person is calling from. It's opened up a world of insights on lead generation for my firm.

Upwork allows you to outsource well-defined tasks such as data entry, research, design, and content. For my PR agency, the best feature is that you can source talent across the world, so you and your team can get some shuteye while lots of tasks still move forward.

Brooks Bell runs an optimization agency in Raleigh, North Carolina. She says, "I'm loving 15Five. It's a simple--and easy--communication tool that helps me stay connected to all 35 of my employees' needs, successes, and ideas--even my junior ones."

Have you ever read an article on your laptop and wanted to share it? Buffer makes it easy to share on multiple feeds at once or to schedule future posts. My agency uses Hootsuite for heavier social scheduling and a few other tools, but Buffer is my personal go-to. I get great feedback from busy executives I introduce to it. Suddenly, it's easy to share the fascinating stories they're reading.

ClickToTweet make it really easy to share a complete pre-made tweet. Like this.

When I need to send a personal note to a small group, such as a board or a committee, this is my tool. Your email will be sent directly from your gmail account and the email addresses in a Google Docs spreadsheet. When I say quick, I mean I can send a merge mail from my draft folder in the time it takes the flight attendant to tell us to shut down.

This application builds quick prospect lists and helps you track outreach. For example, a client at Write2Market was recently hunting CMOs at specialty retailers to invite to an upcoming webinar. SalesLoft helped us find them using LinkedIn search and then transferring data and adding email addresses to a spreadsheet and to Salesforce.

Feedly and IFTTT

Jennifer Bonnett, founder of StartupChicks, says she "automates content marketing. I use Feedly to peruse relevant blogs. Then, when I save for later, IFTTT automatically saves to an Evernote folder. My virtual assistant picks up articles in that folder and writes a synopsis for our blog, with a link to the original source. IFTTT.com automatically posts to Twitter and Facebook, which in turn IFTTT.com automatically retweets/likes as me personally."

Jeremy Goldman, in an article for Inc., named IFTTT one of the top productivity apps to kickstart 2015.

Images on social are important. There are so many tools out there to help, but testing them all can waste your time. International photographer Ross Oscar Knight, who has a studio and photography school in downtown Atlanta, relies on an app that's a couple of years old. "I don't always have time to import my images on my laptop to make changes," he says. "Laminar Pro gives me access to my most-used touchup tools so that my images looked polished, even if they're just for the web."

Did I miss a productivity app you like that's in the "10xer" category?