If your app is content-based and there are some records stored in it, you might want to be sure that your files are not lost after the reinstall.
When simply deleting the app is not an option, you can use the Offload feature that is available on iOS 11 or higher versions.
Let's see how it's done:
First, open your device's Settings and go to the General tab.
Depending on your device, choose the option iPhone/iPad Storage.
You will see a list of all your installed apps. Tap the necessary one (in our case it's the app Coloring Book for Me).
There are two options - Offload app and Delete app. As you can see in the description, offloading an app keeps your files and data saved even if you reinstall the app.
Tap this option to delete the app. On the next pop-up agree to Offload the app one more time.
To re-download it, tap Reinstall app.
On your Home screen, if the app is offloaded, you can still see it's icon. However, there will be a small cloud symbol near it's name.
To begin using the app, you can simply tap the icon. The app will begin downloading.
*Note! Please make sure that you have a stable Internet connection and enough free storage to reinstall the app.
Hope this helped!