Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Prismatic Hexagonalist Pattern No Background
Source GDJ
Prismatic Snowflakes Pattern 3 No Background
Source GDJ