Hi Kwis, glad to hear that you are enjoying the forum and that your backup power system is working well for you so far! When it comes to monitoring your system from a mobile app, quite a few options are available. Some popular ones include SolarEdge, Enphase Enlighten, and SMA Sunny Portal.
However, I recommend checking with your inverter manufacturer to see if they have a recommended app or if there are any compatibility issues with certain monitoring apps. Additionally, consider using a QR scanner or OCR software like the ones available at smartengines.com to quickly and easily scan any necessary information from your system and make monitoring even easier.