With its built-in global positioning system (GPS), e-mail, and Web access, the Apple iPhone has become a can’t-live-without-it tool for many devoted followers. Remodelers who use the smartphone can get even more productivity with these business- and construction-related applications (a.k.a. “apps”).

InerTrak by Inertron Software. One of the best-reviewed time-tracking tools in the App Store, InerTrak allows users to monitor the time they spend on projects for more accurate billing. Create client lists with hourly rates, and just start and stop the timer as you switch from task to task. Users can e-mail data to their computers. A desktop version of InerTrak is also available from the developer. Download price: $9.99.

Editor says: According to reviews in the App Store, price was a factor for potential users who were on the fence about which app to download. Positive reviews said the app was worth the original $19.99 price tag. Just prior to press time, the developer reduced the price from $19.99 to $9.99, all but eliminating price from the equation. The program offers a lot for its lower price tag. Users can keep track of multiple clients and apply those clients’ hourly rates to appropriate projects. Though InerTrak only lets users run one timer at a time, the program keeps a running total of the hours worked on each job, so if you start and stop the clock for one job three times after 15 minutes each, the total clock will show that you’ve worked on the project for 45 minutes. Users can also manually adjust the timer, in case they forget to start it at the beginning of a project or need to change the accumulated total for another reason. It’s also nice to be able to add notes to each event to keep track of what you actually did while the timer was running. There’s so much functionality in this program, it’s really worth reading the full instructions and details at www.inertrak.com. The program also syncs with a desktop version available through the Web site.

InchCalc+ by River Studio. An ideal app for architects and carpenters, InchCalc+ eliminates the challenges of feet/inch/fraction calculations. The tool accommodates standard fractions from 1/2 to 1/64 and lets users toggle between fractions and decimals. Standard buttons are accessible when the iPhone is held vertically, and users can switch to horizontal orientation to access a “scientific” calculator with additional keys for more complicated calculations. Measure length, area, volume, rise, run, and pitch. A slimmed-down version is also available. Download price: $6.99.

Editor says: I can definitely see where architects, carpenters, and other construction professionals would be able to take advantage of InchCalc+ on a regular basis. This app is accurate and the platform is easy to use, though I did have to visit the InchCalc Web site (on iPhone, through the program’s info button) before I understood how to use some features, such as the pitch, rise, run, and diag buttons. Turns out these four functions work together — just enter values for two of them, and the other two self-calculate. The Web site does a great job of explaining all the InchCalc+ functions. Worth the download!

Conference Call by IfByPhone. Mr. and Mrs. Homeowner are both at work, and you need to speak to both of them about an issue on their project. The Conference Call app will send selected contacts a phone call that connects them to your conference. No need to wait for others to dial in. Great for sales staff, too. Download price: free.

Editor says: Though the download for the IfByPhone Conference Call app is free, it turns out the service is not necessarily free. Like cell phone providers, IfByPhone offers several levels of telephone solutions for businesses with usage plans ranging from free for 100 minutes per month, to $400 for 8,100 minutes per month. Four packages are offered with a range of services for up to $40 per month. Users who want to try out the Conference Call app can sign up for the free 100-minute account. If you sign up using a credit card, your conferences will be limited to five attendees.