First of all you should get the news version of the app. It can be found for download here - Cydia Impactor. For this moment the new version has number 0.9.42. It works this way that you add a certificate to the IPA file and you can install the app via iTunes. But the certificate works only for 7 days. Then you need to repeat, because the app will not run. If you want to have longer time you need to invest in Apple Dev Program.