The problem of scale for profitability from ads is certainly there. You could look to use something like admob to start with to make some money back (although the earnings likely will not cover with cost of marketing, without scale). Source: over 1 year ago

1. AdMob Google is the No 1 player in the mobile advertising market. It was already the largest online advertising company when it acquired AdMob. AdMob makes earning revenue easy with in-app ads, actionable insights, and powerful, easy-to-use tools that grow mobile apps. - Source: dev.to / almost 2 years ago

Use online services, such as Google AdMob, for filtering and sorting in-app ads. Source: over 2 years ago

There are different ways to monetize with your Flutter app. You can make users pay to download it, you can have in-app purchase plans, you can let users subscribe using recurring payments to use all the features, or you can show ads to your users. In this article, Dhruv Nakum teaches you how to integrate AdMob into your app. - Source: dev.to / over 2 years ago

Can't say anything about start.io since I couldn't find any decent information about them and their SDK integration. So it's not really clear about them at the moment. Source: 12 months ago

Is it a good alternative to AdMob start.io, I'm getting my attention to give it a try.... Source: 12 months ago

I agree if you are trying to hide from government and or law enforcement this is all futile, however I disagree that only they have access to this data. Companies like gravyanalytics.com, start.io, and heyirys.com all offer mobile location data for sale. Whether or not those companies are actually selling tower data I can't say, or if they are perhaps it is scrubbed first. Privacy policies of the big 3 US cell... Source: about 3 years ago