User Guide

SmartAngle connects to your smart phone or tablet via Bluetooth - so, please check you have Bluetooth enabled from the iOS or Android settings screen.

SmartAngle generates voice messages and warning tones - so, please ensure the volume is turned up on your phone/tablet.

Please check the suppport page if you have any problems setting up SmartAngle and the app.

SmartAngle was developed by QUS in Derbyshire and we hope it will go on world wide sale soon.

Thank you for helping during this market testing stage of SmartAngle - we welcome your comments, suggestions and problem reports.

When SmartAngle goes into production the Apple and Android apps will be available for free download from the Apple and Google stores in the normal way. During the testing stage the arrangements for obtaining the apps are different.

On Apple devices SmartAngle requires iOS 11. Please note this message from Apple.

"The following devices are not supported on iOS 11: original iPhone, iPhone 3G/3GS/4/4S/5/5c, original iPod touch, iPod touch 2nd-gen/3rd-gen/4th-gen/5th-gen, original iPad. iPad 2/3/4.18."

Android buttons

Unlike iOS which is totally under the control of Apple, Android tends to vary from one device to another - manufacturers "tweak" Android for their devices. This can be a problem when trying to explain how to do things.

So, let's agree the meaning of the three buttons that normally appear at the bottom of an Android screen.

From left to right:

  • The back arrow goes back - to the previous thing you were doing, the previous screen in an app, the previous web page in a browser, the previous app. Each press takes you back one step.
  • The circle take you to the menu, normally your home page.
  • The square shows the list of apps that are currently running and you can close an app (stop it running) by swiping across it in this display. Some people are happy with dozens of apps running, others prefer to close an app after using it so their display looks tidy. It's a personality thing!

Pressing any of these can push your current app into the background - Windows users might like to think of this as "minimising" the app.

Some apps continue running while in the background, others do nothing until returned to the foreground by you tapping on it.

The SmartAngle app carries on running while in the background but it turns off voice messages and warning tones.

Obtaining the SmartAngle Apple app

  • Download and install the free Apple app "TestFlight" from the Apple app store.
  • Send us your Apple id - the email address you use when you log on on to iTunes etc. Send it to
  • We will add this address to the list of testers registered with Apple.
  • Apple will send you an email containing an invitation and access code to download the app.
  • Download and install the SmartAngle app.

Obtaining the SmartAngle Android app

  • Before you can download and install the app you will need to set up your Android device to enable installation of "apps from unknown sources".
  • This option is in the "Security" section of "Settings" on your Android phone/tablet.
  • Depending on your device, "Settings" may be reach by swiping down from top right of your screen or from an option labelled "Settings" on your home screen. Different manufacturers modify their version of Android to put it in different places.
  • Once you have enabled this feature you can download the app to your device - or download it to a PC and copy it to your device
  • Find the APK file on your device and click (tap) on it to install it.
  • The app is in the form of an Android "APK" file and may be downloaded from here.

During installation the app will ask for access to various things including camera and location. Please allow it to do so.

Before you start

  • Remove the three 3mm x 6mm Pozi #1 countersunk screws on the back of SmartAngle.
  • If there is a plastic tab under the battery you should slowly, firmly and carefully pull it free.
  • If your battery was supplied separately now is the time to install it - see the photograph below.
  • Refit the screws.
  • If your SmartAngle came with the aluminium level you will find that the corners may be very sharp. They can be taken off with a wipe of a sanding block.
  • Note: your SmartAngle will require calibrating before use - see the "Getting started" section below.
  • Don't forget, the FAQ section of our web site contains answers to many of the questions we are asked.

Information and tips

Obviously Bluetooth must be enabled on your device to talk to SmartAngle.

Do not try to pair with SmartAngle from your device's Bluetooth settings screen - it will fail.

The SmartAngle app handles the connection to SmartAngle - no pairing is required. See "Getting started" below.

  • The app runs in landscape mode only on small screens so the text can be as large as possible. It runs in both portrait and landscape mode on some larger screens.
  • The illustrations in this Guide were captured from an Apple iPod Touch 6th Generation. Things may look slightly different on your type of device.
  • Press the button on SmartAngle before loading the app on your phone/tablet. That way your phone won't go to sleep before it has a chance to talk to SmartAngle.
  • Please read this User Guide!



  • SmartAngle provides an extra hand when levelling
  • Measure in one place and read the angle on your smart phone or tablet at a location convenient for you to see.
  • "Measure there, read here" leaves both hands free for adjustment and fixing.
  • There are two rare earth magnets inside the long side of SmartAngle - so it will stick to any steel surface such as the saw blade shown below.

Preparing the battery

  • SmartAngle is shipped with the CR2032 battery which may be mounted inside.
  • A small insulation strip may be placed under the battery to prevent it draining during storage.
  • If this is the case, remove the three 3mm Pozi #1 screws on the back of SmartAngle, carefully remove the insulation strip then refit the screws.
  • The LEDs on the front of SmartAngle will flash three times then the right hand LED will flash about once a second.
  • The right hand LED will time-out after 60 seconds and stop flashing if you do not connect to your phone or tablet.

Getting started

  • Ensure that Bluetooth is enabled on your phone or tablet - check the "Settings" menu.
  • Do not attempt to pair with SmartAngle - no pairing is required.
  • Press the button on SmartAngle - both LEDs will flash three times then the right hand one will flash steadily.
  • Run the SmartAngle app - see the beginning of this Guide for instructions on how to obtain the app.
  • The app will take several seconds to connect to SmartAngle - so please be patient.
  • The first task is to calibrate SmartAngle as soon as the message below is displayed.
  • Select "OK" and follow the calibration procedure outlined further in this User Guide.
  • Select "Cancel" to use SmartAngle without calibration - it will use default settings.
  • In normal use, after about 5 seconds, the screen will display the current reading in degrees.

Flashing LEDs, timeouts and the "Home" button

  • Both LEDs will flash when you press the SmartAngle button then the right hand one will flash about twice a second.
  • It will stay in this state until it connects to the app via Bluetooth.
  • SmartAngle will switch itself off after about 60 seconds if it cannot connect.
  • The right hand LED will flash much slower after SmartAngle connects - about once every two seconds.
  • After connection, SmartAngle will switch itself off after about 120 seconds (2 minutes) if there is no activity.
  • You can change this "Maximum connection time" in the "Options" menu. Reducing it will save battery power.
  • When the SmartAngle app is running a single press of the "Home" button on your phone/tablet will send it to the background and display your home screen.
  • When in the background the app will save battery power by putting SmartAngle to sleep (no LEDs flashing).

Main screen: degrees, percentages, ratios, falls

Each time the app starts it displays a screen with the value shown in degrees.

Tap near the centre of the screen to select the type of display.



Fall in mm/m:

Fall in in/ft:

Locking an orientation

Tap the SmartAngle icon (lower right) to lock the angle relative to the current icon orientation. For example, if the icon is shown with the long side downwards, all subsequent readings will be shown relative to this position. A lock symbol is displayed when the readings are locked. Tap again to release the lock.

The icon normally rotates as SmartAngle rotates - this shows the surface that angles are currently relative to. Locking prevents this automatic rotation so angles are always relative to the current surface. This means that values will go from zero degrees right round to 359.9 degrees.

Setting zero

Tap the "ZERO" button to set the angle to zero. All subsequent readings will be shown relative to this zero angle. Tap again to return to normal operation.

Turning sounds on/off

Tap the speaker symbol (top left) to disable/enable voice messages and stop warnings.

Changing resolution

Tap "0, 0.5, 0.1" to change the resolution of the display.

Holding a value

Tap the "HOLD" button to hold (freeze) the current reading. An additional button, "STORE", will be displayed so you can add the value to the stop table is you wish. Tap "HOLD" again to release the hold.

Viewing stops

Tap the "STOPS" button to access the table of digital stop angles.

Tap any value to set a stop - tap again to clear it.

SmartAngle uses tones to tell you when you are moving towards or away from a stop - a required angle. A number of useful stops are provided by default.

The image below shows a stop selected at 22.5 degrees so SmartAngle will provide tones from about 17 degrees to 27 degrees with the tone getting higher the closer it gets to 22.5 degrees. The tone becomes continuous when the stop is reached.

See the Digital Stops section for more details.

Using the camera

The SmartAngle app can take a photograph of SmartAngle in use and superimpose the current reading onto the photo. The image may be used for reference or for sending to a client to indicate progress in a job.

  • Tap the camera icon.
  • Take the photograph.
  • Tap "Use image" - this will return to the main SmartAngle screen.
  • You can view and use the photograph in the normal way from your photo album

The example below shows SmartAngle reading the fall in guttering.

Main menu options

Tap the menu (three horizontal lines, top right) to access the main menu options.


Calibration video:

  • Calibration is done in seven steps - rotating SmartAngle between steps.
  • Instructions on the screen tell you what to do for each step.
  • You can cancel calibration at any time by tapping "< Main Menu" (top left).
  • When all seven steps are complete you should tap "Save" to save the new calibration values.

Calibration steps

  • Step 1: SmartAngle facing you, long side down.
  • Step 2: rotated horizontally by 180 degrees - long side down, facing away from you.
  • Step 3: with the long side held against a vertical surface, facing towards you.
  • Step 4: with the long side held against a vertical surface, facing away from you.
  • Step 5: upside down facing you - easily done by holding it under a table top.
  • Step 6: on a short side with the button bottom left.
  • Step 7: on a short side with the button bottom right.


You can select a background colour for app screens.

The slider allows you to select how much gradient (lighter in the centre of the screen, darker towards the edges) is applied to the background colour.

Sounds and other options

Note: you must click on "Save" (top right) to save any changes you make to the options.

  • You can disable/enable the voice messages SmartAngle uses to tell you the angle after the value has stabilised for a few seconds.
  • The "Voice stability time" is the time, in seconds, that SmartAngle will wait for a value to settle before reading it out.
  • You can select the start and stop tones used when SmartAngle approaches any digital stops you have set.

Scroll the screen to see more options.

  • LEDs use power and will shorten battery life when on. By default they do not flash when you approach a stop angle but you can enable them here.
  • The "Maximum connection time" defines how long, in seconds, SmartAngle will stay awake before going to sleep to save power. SmartAngle my be woken up by pressing the membrane switch.
  • The "Show diagnostic messages" function is used during software testing. If selected it will display the raw data from SmartAngle on the main screen

Digital stops

Standard stops

Standard stops are provided with the app.

Custom stops

These are create by you and are displayed in the units you selected (degrees, percentage, ratio, mm/m, in/ft) as well as degrees. See below for details about adding custom stops.

Saved hold points

Stops may also be added directly from the main screen using "HOLD" followed by the "STORE" button..

Scroll the Digital Stops screen to see stops created in this way - they are shown below the standard and custom stops.

Deleting stops

Any stop may be deleted by swiping left on it then selecting "DELETE".

Adding custom stops

Click the plus ("+") symbol (top right) to add a new stop.

Multiple SmartAngles

  • The SmartAngle app will try to connect to the nearest SmartAngle.
  • If it finds more than one SmartAngle within range it will try to connect to the last one you used.
  • If it finds a SmartAngle different from the one you last used it will ask for permission to use it.
  • After giving permission you will have to press the button on the front of SmartAngle to restart the connection.
  • Note: connection will take a little longer if the SmartAngle is not the same as the last one you used.

Changing the battery

SmartAngle uses a single CR2032 button cell battery.

We could have added a circuit to check the battery power - but such a circuit itself uses power and would drain the battery faster.

If the LEDs become very weak, or if weird things start to happen (such as regular disconnection from the app), try changing the battery.

  • Unscrew the three 3mm x 6mm Pozi #1 countersunk screws on the back of SmartAngle.
  • Separate the lid from the base.
  • Use a finger and thumb to carefully unclip the old battery from the holder. (See note below if it is stiff.)
  • Gently push the new battery into the holder with the positive ("+") side upwards towards you.
  • Replace the lid and refit the three screws.

Stiff battery

The clips that hold the battery in place may be very strong - making it impossible to remove the battery with your fingers.

In this case you can use the end of a screwdriver to flick the battery out of the holder.

Take great care that you don't damage the printed circuit board when you do this.

When replacing the battery, first put it into the side of the socket opposite the two longest connectors before pushing down on the other side so that it snaps into place.

SmartAngle support

Please check the SmartAngle support page if you have a problem installing or using SmartAngle.

Warranty (UK)

In the UK consumer rights are protected by the Consumer Rights Act 2015.

In this warranty:

  • "SmartAngle" used alone means the combination of SmartAngle hardware, its firmware and the SmartAngle software app;
  • "you" means the original purchaser of SmartAngle;
  • "QUS", "we" and "us" mean Quite Useful Stuff.

QUS warrantees that SmartAngle is of satisfactory quality, fit for purpose as defined by us, free of defects, safe to use, reasonably durable and as described in this document, on the QUS web site and in QUS marketing material ("the requirements").

  • For a period up to 30 days after purchase you have the right to return the SmartAngle hardware for a full refund should it not meet the requirements. During this period, if the problem is with the SmartAngle App, we may make one attempt to fix it before you can claim a full refund.
  • For a period up to six months after purchase, if we cannot show that SmartAngle met the requirements at the time of purchase, you have the right to a replacement or repair. If an attempt at repair is not successful, or if we choose not to attempt a repair or to provide a replacement, you have the right to a full refund.
  • Beyond six months after purchase you have to show that SmartAngle did not meet the requirements at the time of purchase before you can claim a repair, replacement or refund (full or partial).

In all cases, the limit of our liability shall be the price paid by you at the time of original purchase and we shall not be liable for any consequential loss suffered by you or any third party.

Proof of purchase is required to enable you to benefit from this warranty.

This warranty will not apply if SmartAngle has been damaged or misused.

About SmartAngle®

  • SmartAngle is a development of Quite Useful Stuff Ltd (QUS).
  • SmartAngle is a registered design of QUS.
  • "SmartAngle" is a registered trademark of QUS.
  • "SmartAngle: measure there, read here" is a registered trademark of QUS.
  • "SmartAngle: an extra hand when levelling" is a registered trademark of QUS.
  • SmartAngle firmware and software ("the SmartAngle app") are copyright by QUS.