Well, I finished it: It came out as simple as can be because I really wanted to move on to other 'real' projects instead
The bottom turned out to be wider because of the way I sewed it close: by doing that I've flattened out the material and that is why it became wider. I don't mind too much right now since it's just a test thingie anyway but should I ever want to make something like this again I would definitely do it differently. Actually: I would have started with much thinner yarn to begin with since this comes out rather bulky.
But the upside of that bulkyness is: I know my phone is far less likely to get scratched when it's in my bag and, when I use a larger bag, I am also able to find it much quicker now!
So it is in active service for now
Anyway: the body of the pouch is made on 4 double pointed needles with 2 knit/2 purl. The flap I made in what I think is called "seed stitch" (one purl, one knit on one row and alternate that on the next row so they form bumps on the material) and I played with decreasing on it too: was fun!!
And here's a picture (At least: I hope it worked)