Yes, I think so. It isn't something for me to get rich on – but more like something that I can show "I made this, I had this clever idea" while (hopefully) earning a small income on the side.

When deployed the app will run quite cheaply too – so I', not afraid of losing huge amounts of money on the project.

Maybe you're overthinking this. If your motivation in building this app is to have something to show off a little and earning income is only a secondary concern then the things you mentioned in your original post don't matter. The choice is simple - keep going, finish your app and launch. It's a win-win. If it does well, great. If it doesn't do well it still serves its purpose.