Monetisation

As this is sometimes a topic of debate I want to lay out my thoughts.

Currently

Currently, the app is 100% free to use and users on Android devices can opt to donate/tip via Ko-Fi and "Buy Me A Coffee". On IOS there is no option to donate/tip as it is not possible to use external services to allow donations. I don't want to pay 30% on a donation which also requires me to set up additional infrastructure with additional cost.

Future

The goal is to keep the app 100% free to use without the need for any purchases. (If that is viable)
As it's highly likely that people won't donate I'm thinking about other ways to monetise this.
To accomplish this I'm currently thinking of implementing ads or building a storage solution for files but I'm not sure yet.
As I can understand that not everybody likes ads, I'm open to ideas.
If by any way someone reading this knows about a privacy-friendly ad service, please let me know.

Currently planning on building a privacy friendly ad service

Environment

As WEB3 services, (and digital services in general) have quite an impact on the climate my goal is also to offset emissions via donating parts of any donations/income to some helpful projects. Recommendations are appreciated.