Kestrel Companion (4500)



The Nvisti Kestrel Companion App is the most versatile, accurate and user friendly dual purpose app available. This is a free app for use on your Kestrel 4500 Applied Ballistics and Sportsman. This app allows for both remote viewing for firing solutions and atmospheric data from the Kestrel 4500 AB/Sportsman. This page is dedicated to presenting operational requirements, along with the many features and their proper use. Kestrel Connection to iPhone is not available with this setup. Requires Kestrel 4500 Applied Ballistics Firmware to be 4.93 or higher. Not compatible with Kestrel 5000 Series. To update your firmware use the tool here: Download Page

For a more advanced version, with the ability to use multiple targets, and to manage, upload, and download weapon profiles. See the Pro Version: nVisti Companion Pro.



The following lists the features of the Kestrel Companion app and gives a brief explanation of what they are/do.  Greater detail along with directions for how to properly use all the features is given below in the instructional sections of this page.

  1. Application – The Kestrel Companion App uses the Ballistic Solver built in to Kestrel Device. All calculations are run on the Kestrel, and it requires a Bluetooth Kestrel 4500 Series in order to run. It is compatible with the Applied Ballistics and Sportsman versions.
  2. Single Target Engagement  – Gives you the ability to see a live feed from the Kestrel device. Including environmental factors, and gun parameters. It also allows you to adjust range to target, giving you a firing solution from your Kestrel remotely.
  3. Coriolis Effect, Spin Drift, & Aerodynamic Jump – You can figure in Coriolis acceleration and/or gyroscopic drift (spin drift) into your solution. Both Coriolis effects and spin drift are optional features, easily disabled on the Kestrel device. See Kestrel User Manual for how to disable these.
  4. Dark Theme – A dark theme is used to preserve night vision during low/limited light conditions.
  5. Metric Support – Data inputs/output can be configured to use Metric units.


Operational Overview

The general flow of the program is designed for quick access. Guns are stored on the Kestrel The following sections cover the details of operation.

1. Your Kestrel Applied Ballistics must be on firmware 4.93 or higher in order to use this app. Download Page has the latest firmware updates.

2. Your Kestrel must be paired to your Android device before you attempt to use this app. (See Kestrel Manual for how to pair your Kestrel)

3. Changing weapons must be performed on the Kestrel itself. You can upload/download gun profiles from this app, but you can only change the gun profile currently in use on the Kestrel itself. From AB Mode, scroll down to Gun and highlight it. Then simply press the left and right keypad arrows to change the gun.

4. The compass must be calibrated before you attempt to use this program. If your compass is not calibrated this will not work properly. (See Kestrel User Guide for how to calibrate compass).

5. For Coriolis to be correct, you must input your Latitude on the Kestrel Device itself. (Latitude is found under Environment on AB Mode).

6. Spindrift can be disabled on the Kestrel Device itself from the Environment Menu in AB Mode.

7. Target direction is set on the Kestrel Device itself, and cannot be changed from the app.

8. Units of Measure. Changing the Units of Measure on the Kestrel Device will not affect the Units in the App and vice versa. You must select the units you wish to use independently on the Device, and the App.

9. Batteries – The Kestrel Device is designed to work with Energizer Ultimate Lithium Batteries only, the use of other types of batteries can cause errors and problems. DO NOT USE ADVANCED LITHIUM BATTERIES. The use of Advanced Lithium batteries will cause compass errors, which will not allow you to use wind direction and speed capture. It will also prevent target direction capture.


Main Screen

From the main screen you have quick access to 3 functions. The settings, which can be accessed from any screen by using your phones menu button. NOTE: Before you begin to use this app, make sure your Kestrel Device is paired, and that you visit the settings menu, and properly adjust your settings.


Connecting to Kestrel 4500 AB/Sportsman

You must pair your Kestrel Device to your Android Device BEFORE you attempt to use this app. This process may be different depending on your device. Once it is paired, you then need to tell the application which Bluetooth device is your preference. Click on the Connection Button, this is where you choose your Kestrel device. Simply tap here, and once the menu pops up tap your Kestrel device, and the program will then connect to it. Refer to the Kestrel User Guide, and your individual devices instructions on how to pair Bluetooth devices.

Step 1: Click the Connection icon



If you are having trouble try the Bluetooth Trouble Shooting Guide: Bluetooth Checklist

Step 2: Choose your device.



Connection Indicator: Blue is Connected, Red is disconnected.




The settings are accessed by pressing the menu button, then choosing settings. Regardless of the units chosen on the Kestrel itself, you can choose any units you wish to use in the app.

Changing units in the app will not affect the Kestrel settings and vice versa.



Target Engagement

Single Target Engagement gives you the ability to have a live feed which is updated every 1 second. You will see wind direction, and wind speeds at the top of this screen. Inside the clock direction indicator, you will see your elevation adjustment, and your windage adjustments. Note: The target direction needs to be set in the Kestrel itself, and cannot be changed via the app. At the bottom of the firing solution you will have basic Bullet, Gun, and Environmental data. More detailed data can be found on the Kestrel itself.

Range adjustment: By swiping your finger up and down anywhere on this screen you can adjust the range to the target. You can also fine tune this range with the +/- buttons at the bottom of the screen. You can use the keypad to hand enter a range by clicking on the range number at the bottom, or you can adjust the range on the Kestrel itself. Note: you can adjust the swipe value changes in the settings. So that swiping changes by different increments. Anywhere from 1 to 25 yards/meters at a time.

Connecting to a Kestrel: You must have already paired your Kestrel to your Android Device. If you have not done this, then the connection will fail. Click the Red Kestrel Icon and select your Kestrel Device. Once it is connected/running the icon will turn Green. To disconnect it, simply touch the icon again.

Do not forget to mark the target direction on your kestrel, so the crosswind is correctly calculated.



  • Android v4.4 or higher.
  • Bluetooth support on both the Phone and Kestrel Device is required. (Bluetooth 4.0 or higher is recommended)
  • Region and Carrier Limitations: This app is not approved for all regions and/or carriers at this time. Some carriers may choose to block this app due to the nature of its content.
  • Kestrel 4500 (Not Compatible with Kestrel 5000 Series)
  • Requires Kestrel 4500 Series Applied Ballistics and Sportsman to be on Firmware 4.93: Downloads Page

Not Required:

  • You do not need GPS, Internet, or Cell Service to run calculations.