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 / almost 3 years ago

I use smartmockups.com. Just upload your PNG with transparent background. Source: 9 months ago

By the way, there are sites with free mockup images, https://smartmockups.com/ is one example. Source: about 1 year ago

Have you also googled stuff like this https://smartmockups.com/ ? haven't used it (i have photoshop ;) ). Source: over 1 year ago

Smartmockups.com — Create product mockups, 200 free mockups. - Source: dev.to / over 1 year ago

Well, this exact pillow is from redbubble.com . It's a print-on-demand shop that deals with home textiles, clothing, accessories, mugs, and other products. There are many similar online shops. Artists are using them not just to sell their prints there, but also for getting nice visual examples with their art (mockups). If a shop sounds too complicated for you, you can simply find some digital mockups (of different... Source: almost 2 years ago