BeepChecker is open source software, released under the MIT License. You're free to use it, share it, modify it, or include it in your own projects, even commercial ones, as long as you include the original copyright and license notice. The source code is on GitHub, and the license file is also in the repo: LICENSE.
If you're curious how BeepChecker works or want to suggest a change, you're welcome to take a look at the code. I try to keep it simple, with clear naming and comments, so it's easy to follow and understand. Contributions are welcome - even small ones like fixing a typo. If you find it useful, please consider starring it on GitHub. It helps others discover the project, and it lets me know someone found it helpful.
The full text of the MIT License is included below, for reference.
MIT License
Copyright (c) The Hello World Writer
All rights reserved.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.