Carley Knobloch makes a case for paying for apps:
Here’s how I see it: You know where you stand with a company that makes a paid app. It’s an honest exchange: Company creates a product or service, and I pay you for it, much like I would someone who washes my car or makes me a smoothie. It’s how things have always been done. It just makes sense.
When Company creates a product or service that it gives to me for free, I have to do a lot of thinking about why Company is choosing to do that.
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Companies like Google, Facebook, Snapchat and Apple aren’t altruistic, of course: They’ve built genius services we use every day for free, and while we don’t pay with money, we pay with a major invasion on our privacy. One that we signed up for (go back and read the Terms & Conditions). So, in essence, the business model is you.
Side note: I disagree with her inclusion of Apple there. Apple has proven time & again they are very privacy focused. And they make their money from hardware. Their software and services are something that are value-adds to drive hardware sales.
Beyond privacy reasons alone, is the fact real human beings make software. A developer making an app you love and asking for money is trying to make a living. Paying them supports their lifestyle, and also, frankly, enables further development of the app you love.
If you are unwilling to pay for that app, don't be surprised when it disappears because the developer can't afford to keep working on it.
Now, linking to Carly's article is slightly self-serving in that she uses 1Password as an example, and I make my living from 1Password's success. So yeah, I'm very biased on the paid software front. But please, support your favorite apps and their developers by paying for apps.