When Motorola's Moto Z and its associated modular snap-on expansion units made their debut back in 2016 it was made clear that more 'mods' would appear, and future Z handsets would be mods-compatible. A year on, there are several Z-series handsets and a good range of mods, including third-party ones:
Moto 360 Camera (£239/$299.99)
JBL SoundBoost 2 (£89/$79.99)
Moto Gamepad (£79/$79.99)
Moto Style Shell with wireless charging (£39/$39.99)
JBL SoundBoost Speaker (£55/$79.99)
Hasselblad True Zoom (£135/$299.99)
Moto Insta-Share Projector (£151/$299.99)
Further mods are in the pipeline, including the Moto Turbopower Pack and Incipio offGRID Power Pack.

The Moto Insta-Share Projector is the best of the bunch I've seen so far, but I've now been sent a new batch of mods, including the new Moto 360 Camera. They've come with Motorola's flagship Moto Z2 Force, a premium £719 ($720) handset that ZDNet has already reviewed.
Like all mods, the Moto 360 Camera fits onto the back of a Z-series handset, held in place by magnets and sharing data through a bank of connectors on its bottom edge. The fit is remarkably secure, and because the Moto Z2 Force is a mere 6.1mm thick the camera mod doesn't feel like it adds a great deal of bulk.
Still, it's relatively weighty, taking the Z2 Force handset from 143g to 232g while the camera lens, protruding from the top of the mod, clearly adds height to the phone. There's a rubber cover that protects the camera when the phone is in a bag or pocket, but it still looks a bit vulnerable to me.
The Moto 360 Camera is powered by the handset itself, so there's no need to carry a separate charger or to make sure it has power to get up and running. It's compatible with the Moto Z2 Force out of the box, but other Z-series handsets will need a software update.
The handset recognises the camera as soon as it snaps into place, so opening the camera app immediately uses the mod's lenses, although it's easy to switch back to the handset's camera with a tap of an on-screen icon.
Thanks to its twin 13-megapixel cameras you can shoot 360-degree 4K video at 24 frames per second (fps) and capture 360-degree stills, as well as 150-degree panoramas. You can also share footage direct to social media from the Google Photos app and live-stream to social channels such as Facebook Live.
On-screen you can view the output from both cameras via a split viewer. Auto or manual settings are available to tweak the quality of stills and video footage.
The Moto 360 Camera is certainly fun to use, but it does have its limitations. Image quality is somewhat lacking, for example, with wide-angle stills exhibiting a lot of barrel distortion. And 360-degree stills don't cope very well with wide variance in light and shade between the front and back cameras. For example, I got plenty of indoor stills with glaring white patches where windows are located. It's also a little unnerving that the handset is removed from 360-degree images, so that your hand is visible in shot but it's not holding a phone.
Given that the 360-degree camera market is beginning to grow, and that this particular unit will only work when it's attached to a Z-series Moto handset, it might be worth looking around before taking the plunge.
Moto 360 Camera (£239/$299.99)
JBL SoundBoost 2 (£89/$79.99)
Moto Gamepad (£79/$79.99)
Moto Style Shell with wireless charging (£39/$39.99)
JBL SoundBoost Speaker (£55/$79.99)
Hasselblad True Zoom (£135/$299.99)
Moto Insta-Share Projector (£151/$299.99)
Further mods are in the pipeline, including the Moto Turbopower Pack and Incipio offGRID Power Pack.

The Moto Insta-Share Projector is the best of the bunch I've seen so far, but I've now been sent a new batch of mods, including the new Moto 360 Camera. They've come with Motorola's flagship Moto Z2 Force, a premium £719 ($720) handset that ZDNet has already reviewed.
Like all mods, the Moto 360 Camera fits onto the back of a Z-series handset, held in place by magnets and sharing data through a bank of connectors on its bottom edge. The fit is remarkably secure, and because the Moto Z2 Force is a mere 6.1mm thick the camera mod doesn't feel like it adds a great deal of bulk.
Still, it's relatively weighty, taking the Z2 Force handset from 143g to 232g while the camera lens, protruding from the top of the mod, clearly adds height to the phone. There's a rubber cover that protects the camera when the phone is in a bag or pocket, but it still looks a bit vulnerable to me.
The Moto 360 Camera is powered by the handset itself, so there's no need to carry a separate charger or to make sure it has power to get up and running. It's compatible with the Moto Z2 Force out of the box, but other Z-series handsets will need a software update.
The handset recognises the camera as soon as it snaps into place, so opening the camera app immediately uses the mod's lenses, although it's easy to switch back to the handset's camera with a tap of an on-screen icon.
Thanks to its twin 13-megapixel cameras you can shoot 360-degree 4K video at 24 frames per second (fps) and capture 360-degree stills, as well as 150-degree panoramas. You can also share footage direct to social media from the Google Photos app and live-stream to social channels such as Facebook Live.
On-screen you can view the output from both cameras via a split viewer. Auto or manual settings are available to tweak the quality of stills and video footage.
The Moto 360 Camera is certainly fun to use, but it does have its limitations. Image quality is somewhat lacking, for example, with wide-angle stills exhibiting a lot of barrel distortion. And 360-degree stills don't cope very well with wide variance in light and shade between the front and back cameras. For example, I got plenty of indoor stills with glaring white patches where windows are located. It's also a little unnerving that the handset is removed from 360-degree images, so that your hand is visible in shot but it's not holding a phone.
Given that the 360-degree camera market is beginning to grow, and that this particular unit will only work when it's attached to a Z-series Moto handset, it might be worth looking around before taking the plunge.