Hi guys.
I’ve seen someone with a Iphone who had this app that let him use it almost like a DSLR camera.
I’ve been looking at the camera apps for android and although there are many nice ones I want to know what you can recommend.
Preferably free but am willing to buy it if there is something really good out there.
I’ve been looking for one as well that pretty much makes it a manual camera where I can set the ISO, aperture (as much as you can) and shutter speeds. Would be great to have. I hope someone has a good suggestion. 
I know you said android but I just discovered the iphone has an app that will let you set the exposure time ranging from 1/20s to 1s. It's called Nightcap and there may be a version of it for Android not sure.