Simplify the following text for a Grade 10 native English-speaking person.
Original: Mozilla Add-ons is the official Mozilla Foundation website to act as a repository for add-ons for Mozilla software , including Mozilla Firefox , Mozilla Thunderbird , SeaMonkey , and Mozilla Sunbird .
Simplified: Mozilla Add-ons is the official Mozilla website to store add-ons for Mozilla software . This software includes Mozilla Firefox , Mozilla Thunderbird , SeaMonkey , and Mozilla Sunbird .