With summer almost over and a big Apple announcement on its way, this is a great time to recustomize your iPhone or iPad to help you sell--without spending a lot of money. Here are the 10 best free apps (in alphabetical order) for salespeople:

Over the years, I've had the opportunity to play with at least a dozen CRM systems. Most of them are difficult to use, even on the PCs for which they were designed. Base is the best of a new breed of CRM that's been implemented specifically to run on mobile devices. When I did some writing for Base a while back, I downloaded the app and was pleasantly surprised when I could make it useful in less than a minute.

For years, I've had a recurring nightmare in which I'm in a long, twisty corridor trying desperately to find the right airport gate. Ever since I started using this app, though, I don't seem to have this bad dream quite so often. GateGuru tells me what's happening with my flights so that I can worry about other things, such as why I'm standing in the terminal next to an elephant and am only wearing boxer shorts.

Uhhh, if you haven't heard about this one, where the heck have you been hiding? Seriously, just get it. You'll use it. It will make you happy. It's the Holy Grail of free apps.

One of the biggest hassles of business travel is keeping track of expenses and then writing up the report. This is especially true of salespeople because their expense reports are usually examined with a finer-toothed comb than those of other workers. Expensify takes care of this irritating chore for you.

Travel is, of course, a huge part of your cost of sales. Obviously, you don't want to pay more for your hotel rooms than you have to. When I'm at my PC, I use Orbitz and Travelocity for this purpose, but I find their mobile apps to be a bit clunky. This easy-to-use app focuses like a laser on the best hotel deals that you're likely to find this side of AirBnB.

This book-reading gem might seem like a stretch as a sales app, and it's only free for a week, but I end up using it more than any app on my iPhone or iPad because it gives me unlimited access to thousands upon thousands of top-of-the-line books on business, sales, and marketing. (My own publishers don't yet support this app, so you can't get any of my books this way, alas.)

If you're serious about documents, you might want to think about Microsoft Word for iOS ($99 a year). And if fancy presentations are your thing, go for Apple's Keynote ($9.99). Spreadsheets … shrug. But if you're all about free apps, it's hard to go wrong with the basic version of Quickoffice. I've used it for about two years with few or no complaints.

This app is so simple that it's almost silly. Until quite recently, I was still using my leather FranklinCovey day planner to keep track of what I needed to do because the mobile to-do apps that were available felt artificial and stilted. I don't know exactly how to explain it, but this app "feels" like it belongs on a mobile device. Absurdly simple to use.

Maybe it's just me, but I often find it difficult to sleep the night before an important meeting. I use this app to calm myself down after a hectic day and when I simply must be well-rested on the morrow. Hey, it's not Ambien, but it's pretty damn close.

Back in the olden days of the flip-phone, I used to print out all the different emails from the airlines, the hotels, the rental cars, and so forth, and laboriously transfer them into a neat little form in my dayminder. Many times this "single collection" of travel information kept me on schedule. As useful as that activity was, I don't do it anymore, because this app does it for me. I guess I'm just getting lazy.

Note: Since I don't use Android, I didn't include any links to versions of these programs running on that platform. However, most of these freebees are available there, too.