(Feature) Adding Finance Tools about converternow

[ferraridamiano]

Hi again @fux0r2009 and thanks for all your suggestions!
My plan for the future is to also add a tools section in the app with all these things and much more. However I don't have too much time to work on this. I can work on this project just few hours a week.
I will close this issue for now because I first need to structure the tools section as mentioned in issue #6.
Regards!

[avipars]

@fux0r2009 agreed, https://unitmeasure.xyz/ has the tip calculator covered, as for the other features... they would be great in either app (unfortunately, I don't know dart/flutter too well) . Focus is primarily on java/kotlin

[ferraridamiano]

Hi @avipars, please avoid to do marketing here. This isn't the rigth place, I'm sorry.