None of these require jailbreaking or sideloading.

Many apps offer free trials or have freemium models that allow users to access basic features for free.

Free developer certificates limit you to three sideloaded apps at a time, and they must be resigned weekly unless you use a paid Apple Developer Account or a permanent exploit like TrollStore.

—offered a unique puzzle-based approach to soccer. Instead of full matches, players used intuitive swipe controls to recreate over 500 iconic real-world goals from the last 40 years. Internet Archive

If you have legally obtained an IPA file (e.g., you backed up your own app) or are proceeding despite the risks, here is the technical method to install it on a non-jailbroken device.