so the thing is : you test an app and you get the new built so you have to delete the first built can you get your progress on the new build ? or do you have to start at the beginning?
Good question, have yet to discover it myself, however my assumption would be that it would not save your data.
You have to start all over. But if you have your idevice jailbroken, well thats another story. I personally have not jailbroken mine, but Ive heard of people downloading something and then they dont have to start over, but I cant remember the name right now.
Each beta will replace the previous version and at least from my experience, all data from the previous beta will be removed.
I have one called AppBackup and it works wonders. While if there's a major update between betas it might not work, it more often than not does work fine. I've used it to keep progress from one beta to the next. Just make sure the name doesn't change or anything like that, otherwise the data won't work. There's another method but it's a somewhat long process to describe here. It'd just be easier to go with the AppBackup method as well.