Apple iPhone OS 4.0 is out, not without issues

It won’t work with the original iPhones of 2007, which may force users of these phones to upgrade to the new devices

The look and feel of the system has changed, with a 3D quality to them. Users finally get some of the multi-tasking capability users of devices like the Android have been used to. There is also the ability to group apps into different folders.

There is improvement in the iPhone’s mail capability. It supports multiple accounts which you can access with a single inbox. There is also improved spell-check, where iOS4 gives its own opinions above the word.

The iBooks app reader is also out which means you can use the iPhone as an eReader. It is likely more aimed at iPhone 4 devices with its better imaging quality and obviously the iPad.

Unfortunately some users have reported problems, such as phones crashing, contacts entries disappearing and phone call problems. But a factory reset as well as a phone re-sync seems to solve most of these problems.

The iPhone 4 is launched tomorrow.