Just over a year ago, a startup company called OnePlus announced it would launch its own Android device that would compete with flagship products from entrenched bigwigs like Samsung. The oddly-named OnePlus One would go on to sell for just $300 with excellent internal components. For an operating system, the team at OnePlus allied with Cyanogen, and signed a nonexclusive agreement to distribute Cyanogen OS.

While the phone met with rave reviews, the company had trouble shipping the devices in volume, and used a troublesome “invitation” process, which basically translated into “You can buy a phone an indeterminate number of months from now.” The real trouble came in India — when OnePlus went to distribute the device in that country, it found that Cyanogen Inc (the manufacturers of Cyanogen OS, but not the popular CyanogenMod) had signed an exclusive distribution agreement with Micromax Mobile.

This trade dispute gave OnePlus additional reason to develop their own version of Android, which they’ve now done — the result is the OxygenOS, which will ship as default on upcoming OnePlus Two devices. According to Cyanogen, however, the reason for the split is different. Microsoft has been aggressively courting Cyanogen — the two companies inked a deal last month to bring OneDrive, OneNote, Outlook, and Bing over to the Android platform — and Cyanogen’s CEO, Kurt McMaster, has said that OnePlus was a great first partner, but he wanted to move on to bigger and better things.

“OnePlus shipped reasonable volume, but nothing compared to what some of these other partners can ship,” McMaster told the publication, “so we are working with partners that can scale much quicker.”

OnePlus finally managed to kill its invite system for the OnePlus One, but has announced that it will use exactly the same system for the upcoming OnePlus Two. Specs for that device have yet to be announced, but it’s reported to be shipping towards the end of this year. That suggests either a 20nm SoC from Qualcomm (either the Snapdragon 808 or 810), or the not-yet-released Snapdragon 820, which is built on 14nm technology at Samsung. The screen is bumping up to 2K, with 4GB of RAM and a reported battery size of 3300 mAh.

Thus far, the OxygenOS build that’s available for the OnePlus One has been hailed as a stock Android experience — possibly a bit more stable than Cyanogenmod 12, but with far less customizability and fewer options overall.