TS1702: iOS: An app you installed unexpectedly quits, stops responding, or won’t openLearn about iOS: An app you installed unexpectedly quits, stops responding, or won’t open
If the app is not working as described in the store then try the 'report a problem' link from your purchase history : log into your account on your computer's iTunes via Store > View My Account and you should then see a Purchase History section with a 'see all' link to the right of it ; click on that and you should see a list of your purchases ; find that app and use the 'Report a Problem' link.
Thank you got the advice. I realized that I left out essential information -- my laptop fell whilst in operation, and is in the shop. I have only my iPhone to solve this. I began searching for an answer within 2-3 minutes after buying and opening the app, do I have yet to receive an invoice via email. I started looking quickly so that it was clear by the times that I found out immediately and tried to solve things.