About the app, lets say you have a young kid who has a smartphone and you want to know, with who he chats, what he watches on yt, what sites he visits and etc.
We are not registered as business, after we pay for servers we make enough for a dinner and a movie. It's nothing serious.
Because we do not make enough to quit our day jobs let alone hire lawyer is there way our app can survive in EU or do we have to block access?
You’re not complying with numerous other regulations like business registration, tax licenses, etc. The reality is all small businesses have to ignore compliance to get off the ground.
Don’t listen to others trying to scare you over nothing. It’s a matter of perspective.
The problem I see with your application is the consent. You need specific consent by a party, say it's a legal guardian. I'm not sure if legally, in all EU countries, a parent can monitor a 16 or 17-year old's mobile. What happens if a parent installs your app to a 16 year old and leave it there when he turns 18?
From what you're saying it's not even worth pursuing, I mean you basically need a expert's law advice in every one of the 25+ EU countries.
As long as you are looking into GDPR and how it affects your business you can evolve it over time rather than completely change everything by the 25th.