Solar Panel X, developed by Revolna Workshop, is a free Android app that helps you optimize the usage of your solar panel. With this app, you can accurately forecast the energy generation of your solar panel for up to three days in advance.

The app features detailed charts displaying the forecast production for the next three days, allowing you to plan your energy usage accordingly. Additionally, Solar Panel X provides a helper for the installation of your solar panel and allows you to calibrate the forecast. The daylight map feature is also included to help you determine the optimal placement for your solar panel.

One of the best things about Solar Panel X is that it is completely ad-free. However, it's important to note that the accuracy of the energy generation forecasts is currently at 70% for up to three days and 40% for more than three days. The developers have promised to improve the forecast engine in future updates to achieve an accuracy rate of 90%, similar to regular weather forecasts.