Essential, Android co-founder Andy Rubin’s new smartphone venture, is working on a follow-up to the Essential Phone (PH-1).

The startup's first phone had a rough go of it last year, selling fewer than 90,000 units in its first six months on the market, according to industry research firm IDC. It's sill a long way from becoming a success, but it has some of the best expertise in the business, including with Rubin at the helm, so it should be able to push through and possibly have a bigger hit with the Essential Phone's successor.

Designers at Essential have already confirmed that the Essential Phone 2 (PH-2) is in the works. Here's what you need to know.

There was a lot of confusion surrounding the name of the first Essential Phone, as Essential has teased it with the name "Essential Phone", but it later gave the handset the full name of "Essential Phone PH-1" to presumably help differentiate it from next-generation models to come.

In a Reddit AMA at the end of 2017, the designers of the first Essential Phone, Linda Jiang and William Leggett, confirmed that they were already working on a follow-up phone and that it's now called PH-2: “We are definitely plugging away at PH-2. No time to waste," they wrote.

A senior researcher at IDC also claimed a new Essential Phone is on the works. In a tweet from MWC 2018, he said the information was confirmed to him by Markus Weber, Essential's lead software program manager, during a conversation about what's coming next for the company.

Unfortunately, very little is known about this upcoming device. In a Reddit AMA at the end of 2017, the designers of the first Essential Phone confirmed they are working on improving the "display/glass durability as much as possible" in next-generation phone.

At MWC 2018, the Vivo Apex, a concept phone, popped up with small bezels, an in-display fingerprint sensor, and a popup front-facing camera. Shortly after, Rubin tweeted out a patent for this same camera setup. It was granted to Essential in May 2016. It also described another implementation, in which the camera is mounted on the top-left corner of the screen and acts as a permanent camera icon.

Keep in mind a filed patent doesn't mean that the company will actually use it. However, since Rubin decided to show off this patent on his own, it makes us wonder whether the PH-2 will ditch the first Essential Phone's notch in favour of a pop-up-style camera.

Benjamin Geskin is a leaker who has surfaced some spot-on leaks in the past about Apple's devices. However, more recently, he tweeted a concept image for the Essential Phone 2 (PH-2), with the caption: "18:9 QHD+ OLED Display". It's unclear if this concept is just Geskin speculating about the upcoming phone's design and features or whether he knows what Essential is cooking up. Either way, it's interesting.

After months of teasing by Essential, the first Essential Phone debuted in May 2017 and was supposed to release the next month in the US, but it missed that target. The Essential Phone was then confirmed to start shipping in August, according to an email sent by Rubin to customers. Judging by this timetable, we can expect the PH-2 to be teased in March, possibly unveiled in May, and released by this summer.

However, Essential hasn't confirmed any of that - and since the company has a history of launch delays (not just with its phones but also with its modular accessories), we're not sure the Essential Phone 2 (PH-2) will release this summer or even sometime this year.

So, Essential has confirmed it is working on the PH-2, but, oddly, it still hasn't even released the first one in the UK. Essential was said to be in talks with several UK carriers, including EE, to finalise a launch date for the device. Those plans seemed to have fallen by the wayside. It's therefore unclear what's happening there, but since the first phone is available in the US, we can assume the PH-2 will be too.