James Hague:

It’s also worth taking a step back and looking at the overall marketplace. Maybe you love developing 16-bit retro platformers, but what’s the overall level of interest in 16-bit retro platformers? Is there enough enthusiasm to support dozens of such games or is market saturation capping your sales? If you’ve written a snazzy to-do list app, what makes it better than all the other to-do lists out there? Can folks browsing the app store pick up on that quickly?

There’s a two-fold issue at hand here.

The first is that we’ve got app store saturation. No one cares about your app – you need to build something that solves genuine user problems.

But that also opens other opportunities: to target niche markets and do one thing really well. To Do apps? There are a million of those, but there may be a certain industry that you personally know really well that needs problems solved. If you can target this market creatively, and get the message out, you have an opportunity to make a moderate side income.