Ok, you can throw away your German grammar books now, or at least rip out the chapters about German gender and articles. Awesome! Genusly is a great tool, that lets you type or copy&paste a text in German, and it will tell you the gender of the nouns:
So the colour tells you the gender, and then you can decline articles or adjectives according to the gender correctly, and yeeeeeah, you might need your grammar books again for this, sorry :)
Have fun with this great tool!