IPhone OS 4 will be unveiled on Thursday

Apple will unveil the iPhone OS8 in Cupertino on April 4th.

Although Apple is still officially listening to the matter, invitations have already been sent out.

The main novelty of the OS will be that third-party software will be allowed to run in parallel, and it is very likely that version 4 will also support video calling. It is not yet known whether this service will be active only on the iPhone that arrives later, or whether 3G and 3GS users will also receive it. The upgrade will certainly be free for iPhone and iPad owners.