A mobile tech stack is like a triforce: you need marketing, tech and data to work hand in hand so you can get the best benefit from it.
I think you need:
- Analytics: to track your user behavior and make sure you can understand where are the biggest opportunities in improving your product (funnel drop-off, feature education, habit building, etc..)
- CRM: I like to think of CRM as an extension of the product, it should add additional depth on the way your user experience your app.
Don't focus on weekly newsletters or promotional campaigns. Think about tackling Activation, Engagement, Retention & Monetization when your product is not enough (yet).
Feature education (emails for users who never tried a specific feature) / funnel winback (push notification if the user didn't finish the onboarding) / etc..
I don't believe an attribution provider (MMP) is a requirement when you're getting started. Unless you're scaling your UA on different channels. If you're starting with Facebook for example, you can just set up conversion events and optimize everything from their dashboards.
Don't forget to add a crash analytics tool, especially important to monitor your product if you're launching it (e.g.: impact on ASO for the playstore).
If you're already set up with the above and have some budget left, you should integrate:
- some deeplinks: helpful to redirect users to the correct content.
- A a/b test framework (or an internal setup) that allows you to test the different funnels in your app (onboarding, purchase, etc.) by iterating on design, UX, screen order, etc.. Quick tip: you can easily set this up for free if you have talented engineers that knows how to use variables. You can also use your CRM as a A/B test tool with in-app messages.
Additionally, if you're a game you'll have a monetization framework, even if you should aim to keep a pretty low ad frequency until you've optimized your game.
I don't think being more capitalized or less should change your setup, it should change the tools instead. If you have 0 budget, you won't be going for the best in class.
I can't give tools names in my answer, but there are plenty of great tools for each topic!
I hope this is helpful :)