Building an app is now fast and easy. You can build an app based on the prebuilt designs and features offered by the app builders for free. Most app builders will offer free app building and require you to have a monthly subscription to publish your app on the App Store. Once you stop your subscription plan, your app will be removed from the App Store. Some other platforms let you develop and publish the app for free but with the advertisement. However, you can check out some complete free app builders such as Apps Bar.