These people have been urging Android app users to pay huge sums of money for even the simplest applications such as automatical calculation or barcode checkers after they forgot to cancel the app after its trial period. Normally, the trial time is given to each user for checking the app and its abilities for a particular time period, e.g. a week, month, etc. with no fee. In addition, people have the possibility of uninstalling the product if it did not seem to fit expectations.