"Growing Answers", on youtube, did a test and review of this new par meter app called "Korona". He also compared to an Apogee MQ500 par meter. The results are pretty damn impressive. Watch the video if you're gonna try it out, he gives valuable instructions/tips on how to set up your phone and use the app for accurate results. Right now it's just iOS, if you have an iPhone, please go try it out and share some results - that would be cool.
I hope it comes out for Android. If you have an Android phone, you can go to their webpage, scroll to the bottom, and sign up to be notified when it's available (and it might spur them on if you do, too): https://growlightmeter.com/
Here's the test/comparison:
I hope it comes out for Android. If you have an Android phone, you can go to their webpage, scroll to the bottom, and sign up to be notified when it's available (and it might spur them on if you do, too): https://growlightmeter.com/
Here's the test/comparison: