Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Prismatic Abstract Geometric Background 5
Source GDJ
Sort of reminds me of those old house wallpapers.
Source Tish
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin