V1.4.3 Bug which fail to buy additional item is corrected. V1.4.2 Bug Fixed. V1.4.1 Bug which some parts do not appear from a specific model is corrected. A package reset function is improved so that only an answered problem may be reset. V1.4.0 Tablet is supported. The function reset collectively was added. V1.3.0 The sound effects sounded when you input an answer were added. It enabled it to purchase a puzzle by In-app Billing.