Ecosia (https://www.ecosia.org/) is a search engine based in Germany which spends most of its profits in reforestation efforts by collaborating with local non-profit organizations. They also publish their monthly financial reports here: https://blog.ecosia.org/ecosia-financial-reports-tree-planti...

Disclaimer: Not related to them in any way but recently came to know about them when they hit the 100 million count of trees planted.