Translation of Kosmetikerin

My brother moved there last year. He met a woman and went after her. After six years they have broken up, but he no longer wanted to return, because he has settled down in his new home. I am visiting him once a year.
Maybe we would need to say install our dictionary as a software? But I would say instead of install, use our dictionary as a software. So bottom line. If I use the singular form for newsletters and websites, I am on the safe side for both?
I can already speak a little English but not too well. So I'm more cautious about making mistakes. I want to improve my English, because it is also good for your confidence and communication skills.