Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Prismatic Curved Diamond Pattern No Background
Source GDJ
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Polka Dots Mark II No Background
Source GDJ
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
Light and tiny, just the way you like it.
Source Rohit Arun Rao
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A new one called white wall, not by me this time.
Source Yuji Honzawa
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Prismatic Triangular Background Design Mark II 5
Source GDJ
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo