A set of paper filters. The base texture is generated the same way, only the compositing mode is varied.
Source Lazur URH
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Sharp pixel pattern, just like the good old days.
Source Paridhi
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
Prismatic Abstract Background Design No Black
Source GDJ
Element of beach pattern with background.
Source Rones
A pale olive green background with a seamless texture.
Source V. Hartikainen
Black And White Floral Pattern Background from PDP.
Source GDJ
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers