Filter App Store searches?

One problem with there being so many apps in the App Store is that sifting through all the results can be a little cumbersome. For example, there are dozens of text to speech readers. I want an app that is just a one-time purchase and doesn’t require a monthly or yearly subscription (I don’t mind paying for an app, I just don’t want it to be a steady drain on my budget). Searching through the dozens of apps for this category on the App Store, I see a tag on virtually all of them that they include an in-app purchase, but there is no tag tells you whether they involve a subscription or not. Is there a hidden way to filter out those that involve a subscription? When virtually all apps in a category offer an in-app purchase, the “in-app purchase” tag becomes less and less useful.