Lightmeter

Measure your surroundings

Knowing how much light your are exposed to enables you to make changes where they are most necessary. Factory calibrated sensors can be had for cheap nowadays, but even better: your smartphone already has a sensor integrated! Installing a “Toolbox” app lets you access all the internal sensors of your phone, including the light sensitivity meter. It is important to note, however, that these tiny phone sensors can not match the accuracy of a real lux meter and can be off by a significant amount, especially in an extreme dark or light environment – so do consider it more as a rough estimation, but that should cover our use case nevertheless.

Our personal favourite app is the Physics Toolbox Suite for Android, as it is free, comes without advertisements of any kind and gives you a ton of possibilities and option (even exporting graphs to Excel if you want).
On iOS we really like Light Meter LM-3000, because it comes with better calibration than most other apps and is free to use for long enough to take your measurements.