"You can also try converting installed app into *.IPA using Filza. Here's how you can try that.
Requirements:
Filza
Target app for installed on the device and working properly (not crashing or prompting Apple ID)
Appsync
Jailbroken iDevice
Instructions:
1. Let's take "Perk Wallet" for example. Open Filza and Find out where Application folder is. Usually it can be located in /var/mobile/Applications OR /var/containers/Bundle/Application yours will be one of these too. If it's not one, it's the other.
2. Find the folder of the app you want to convert in Applications folder. It is organized by name and there should be another folder in there with the extension .app.
3. Tap Edit, select Perk Wallet.app, and tap Copy.
4. You need a "staging area" to build an ipa file. Recommend /var/mobile/Documents. Go there and make a new folder and label it. Here label it as Payload. You must name it exactly that, or this will not work.
5. Enter the Payload folder, and paste the Perk Wallet.app you copied earlier by tapping the clipboard icon and then Paste.
6. Only Follow step 6 & 7 if you want to install that ipa as a duplicate other skip to step 8. Go into Perk Wallet.app and find Info.plist. Tap it and it will open in Filza's plist editor.
7. Find CFBundleIdentifier, and tap the info button. You need to change the value so it is unique. Here we put "2" at the end. Then go back, tap Save, and then Done.
8. Go back 2 pages so now you are in /var/mobile/Documents. Tap Edit, select Payload, choose More, and tap Create ZIP. This will make a new file called Payload.zip. Tag Edit, select Payload.zip, and choose Rename. Change zip to ipa. This should leave you with a file named Payload.ipa
9. Now tap Payload.ipa and choose Install. If it says Done, congrats!