While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
There are so many out there forsale or on the market. To start you should have something that will handle the weight of your camera. If your camera over weights the arm it will not stay level. Moving smooth without noise is another good point. These arms run from $60 El cheep O to 400-$500 bucks for quality.
Here's one I can build for you for $150.00 + shipping.
No matter which one you choose, be certain it has a ballhead where the camera screws on or you will never get the camera pointed in the right direction or level.