Segment is more a data service, they collect data and pipe it to other services for analysis. I find it useful, but its probably better to just go directly with the analytics framework if that's all you want. I've had great success with Mixpanel, but tried Amplitude and also enjoyed it. More on reddit.com

PostHog, I honestly haven’t found a more developer friendly solution out there. And it’s also open source, so you can self-host it if you have strict privacy concerns. I think it took me like 2 days to set it up and connect it to the product at work (which is built with Flutter) and it took me a day to connect it to my side-project (which is a web app, not Flutter) but to be fair PostHog works really well with websites, but it’s not too bad with Flutter (except windows flutter applications for some reason) More on reddit.com

Big One. First thing I would do is investigate competitors a little further. Not want to bias you, but Firebase really is not a great solution. We did implement it and switched to another service. This can be avoided... Major view parts of the app I would track as screen views. A banking app for example, has an account view, a dashboard and a settings part. I would track those as screen views. Most Apps put those parts in their bottom bar. Events should be every user interaction/click. Make sure if you have different entry points to set an event property that tells you where the user opens this set of feature (maybe from your settings view or your dashboard). This will give you great insights. When it comes to event properties make sure you track those. They are highly dependent on the app you develop. User Properties! You should definitely find an interesting way to segment users. Check out your personas and see if you find properties that makes sense to segment. Let's revisit the banking app. You might want to have a look at users that have merely a savings account. Just to see how these users actually use your app. They probably interact a whole lot different than users that have a checkings account: retention, logins etc. Taxonomy is key. Really. Be smart about that. Especially if you want different (non technical) stakeholders to the use charts. Also check out apple's IDFA opt out in iOS 14 (announced at wwdc). You should be aware of that change. Not really concerning in app tracking, but should be in your mind for a future setup. More on reddit.com

Use TIMESTAMP WITH TIME ZONE instead of TIMESTAMP as the column time. What's app_clicks recording? total_clicks from whom? I don't see any foreign key constraints - not sure if that's intentionally left out. More on reddit.com