Google has officially announced its launch event for 29 September. Pocket-lint has received an invite to the launch where plenty of "treats" are expected.

Google generally uses these annual events to launch new hardware in the form of its Nexus devices. That usually means the latest version of Android is also unveiled. The wording of the invite refers to "treats" and Google's Android is always named after a "tasty treat".

This year Google is not only expected to launch two Nexus smartphones along with Android 6.0 Marshmallow, but also a new Chromecast 2 dongle.

We've rounded up everything you can expect to see at Google's 29 September launch event.

The Nexus 5X is rumoured to be built by LG, an already-standing partner of Google when it comes to Nexus. This device is expected to be the smaller of the two Nexus handsets to appear.

READ: Nexus 5X: What's the story so far?

Rumours suggest this will be called the Nexus 5X and will feature a 5.2-inch display. It will have a full HD display (1920 x 1080 pixels) for 423ppi.

The Nexus 5X will come powered by a Qualcomm Snapdragon 808 hexa-core processor backed by 2GB of RAM. We expect to see both a fingerprint reader and USB Type-C on the handset. It should cram a 2,700mAh battery in a 8mm thick body if rumours are correct, finished with a plastic back.

The camera should be a Sony 13-megapixel snapper with LG's laser autofocusing.

This year a second, larger Nexus, is expected to appear made by Huawei. This is will be known as the Nexus 6P.

READ: Nexus 6P: What's the story so far?

The larger Nexus is expected to feature a larger screen at 5.7-inch with a 2560 x 1440 resolution for 515ppi. This should be crammed into a 6.6mm slim body with slightly raised rear camera of unknown resolution. This should all sit in a metal build .

Powering the Nexus 6 is expected to be a Qualcomm Snapdragon 810 processor, storage options 32, 64 or 128GB, fingerprint scanner and USB Type-C.

The newest version of Android is expected to appear on the new Nexus devices before rolling out to other handsets. In the US invite, Google says "join us for some tasty new treats and s'more". The "s'more" part is dropped for the UK invite, but it's a direct reference to a Marshmallow treat.

READ: Android 6.0 Marshmallow preview: What to expect from your next version of Android

Things to expect include deep support for Android Pay, USB-C for faster charging, fingerprint sensing and more.

The familiar material design will run the show but with improved volume controls. Now you can once again get access to volumes from the rocker button along with smarter settings like alarm volume remaining on while the handset is set to silent.

Peeking is an offering that will allow the user to control notifications for each app to the point of turning off those appearances at the top of the page, or over the top of an app. Hardware permissions are also accessible so you can turn off location access for Facebook for example.

Now on Tap supercharges Google Now, bringing smart searching to any page of your device to make it easier to find the information you're looking for.

There should be plenty more revealed in the final version on launch day.

While the name isn't certain, it's pretty clear we can expect a new Chromecast to appear at the Google event.

READ: Google Chromecast 2 release date, rumours and everything you need to know

Leaks suggest the new dongle will change shape for a more rounded look. The hardware should be improved with better Wi-Fi for "Fast Play" plus an ability to pull in feeds, presumably social like Twitter, to be used as a "backdrop" screensaver.

Spotify support is also expected to be announced. But this could go further since Chromecast is apparently adding another device called Chromecast Audio. This should feature a 3.5mm audio jack that will allow these to turn any speakers into a multiroom system, able to stream Spotify and more.

Finally the app should also get an update with new "What's On" and "Discover Apps" sections.

According to Android Police, Google plans to announce a family plan option for Play Music while at its Nexus event on 29 September. The company will reportedly also unveil new phones and Chromecast 2 at the event, but amid all those announcements, Google will reveal its family plan costs $14.99 a month and includes unlimited music streaming for up to six accounts.

Spotify, Apple Music, and plenty of other competing services currently offer households with multiple users the option of paying one monthly fee. Otherwise, every person in the house would have to pay for their own, individual plan. Play Music always made users get their own plan, which is of course not very user-friendly, but it looks like that's all about to change.

READ: Google might introduce a Play Music family plan 

According to Android Police, which also recently claimed Google is getting ready to unveil a Play Music family subscription at its big Nexus event, the Mountain View-based company is currently developing a tablet named Pixel C. It is an Android-powered device, rather than Chrome OS, and it'll feature a 10.2-inch display with 308 ppi and 500 nits of brightness.

The website stressed that the tablet could get cancelled, but as of right now, it is in the works and expected to run a Nvidia X1 quad-core processor, Maxwell GPU, and 3GB of LPDDR4 RAM. Other features include a glowing bar on the back that indicates battery life, a USB Type-C charger, and a build quality that'll mirror the rest of the Pixel line (so expect a metal design).

There's no word yet on pricing, but it might be on the expensive side when it launches sometime around November. Google might also unveil the upcoming tablet at its Nexus event.

READ: Google Pixel C tablet likely in the works, running Android

Now it's time to sit tight and get ready for the event where we will be to get hands-on experience with all the kit. Expect most of it to become available shortly after the launch day.