Identifying CMS

Ive spent a fair amount of time trying to work this one out, to no avail. Basically, I'm looking to identify what CMS a previous developer has been using with a client I have just taken on. It only administers half of their website, and in order to go forward with the project, I would like to know what it's utilising.

I have reverse image searched the logo and found a couple of sites using the same system, so I know it's not a bespoke system however I can't find any clues in the code or on BuiltWith etc.

I almost feel i recognise it, but can't put my finger on it. The logo is a blue, 3D cube and it makes use of Bootstrap.

I have found what looks to be the same system running on booter.io and booter.in, along with elitephysics.in. I have attached a few screenshots, including a blanked one from my clients login page.

Any help on this would be much appreciated in order for me to move forwards with my project.

--Seems I cannot post images due to low rep, so heres a imgur gallery containing: http://ift.tt/16LL0hl

Thanks guys!