There are plenty of great construction-oriented smartphone and tablet apps out there, and more are popping up every day, but sometimes KISS (keep it simple, stupid) is the way to go. Here are several of my favorite utility-type mobile applications that you may not have considered. If you don’t like these, there are loads of similar apps out there in each category — just search the AppStore (iOS) or Google Play for Android.

Illuminating app: Don’t laugh, this has turned out to be something I use almost every day. The best ones use both the camera’s flash LED and the screen itself for brightness and will light up any dark crawlspace. I use one called “Flashlight” for both iOS and Android.

Tallying apps: These let you keep track of things you’re counting while you’re counting them, e.g., the number of sinks on a blueprint or the number of windows in a house you’re bidding. “TallyPad” is the one I use on the iPhone and “Tally Counter” on Android.

More than just notes app: While it’s tempting to take notes on your device’s built in “memo” app, don’t. Instead, sign up for Evernote’s free version and use the Evernote client designed for your device. Add photos, documents, or even voice recordings. Organize your notes into “notebooks” or use “tags” — or just dump them all in a big digital “pile.” You can easily find them again with a clear text search.

Photo markup apps: These allow you to mark up and add notes on your phone-cam pictures — invaluable when bidding or trying to document jobsites. “My Measures and Dimensions” is a really good one for both iOS and Android. There’s a free version available, but spend the $5.99 on the Pro version and you get: a back-up system (not included in the free version); more folder/project support; and zoom capabilities on your photos (like CAD files). Also, the various markup tools are more precise and there are no ads or nags.

Another essential photo markup app is Evernote’s “Skitch” — available for both iOS and Android (as well as desktop computers). Skitch includes all the Web-capture, redline, and text tools you’ll need and, most importantly, makes your Skitch files instantly searchable in Evernote.

Document scanning apps: Who knew your phone would make a great mobile scanner — perfect for any scraps of paper you need to process on the jobsite. The best scanner apps will produce clean PDF files. “PDF Document Scanner” is a decent free one for Android, and I still like the “Jot Not” apps the best (iOS, in beta for Android; free to $4.99 depending on features).

Along those same lines — sometimes you need to plant your John Hancock on one of those “phone-scanned” documents before you send it on its way — “DocuSign” has become a de facto standard, accepted just about everywhere, but “pro” accounts incur a monthly fee. SignEasy is another good bet, with both annual ($20) or pay-as-you-go ($4 for 10 documents) plans.