The image patterns can be created in Photoshop as well as 99% other applications by very much the same method. It is not the most amazing tiled design but it is still a seamless design that can be captured and used as a tile design
Open a picture and then select menu and select all and edit menu and copy. OK, now you have the photo in the pasteboard / clipboard. Now you need to resize the canvas or photo (canvas is OK). Image menu and canvas size and set the anchor to the top left and set the drop down to percent and set the percent for width and height to 200%
You should now have a document with the photo in the left corner and the rest of the document filled with the background color (white etc). You now need to fill the other three corner. Paste the stored picture three times and place into the top right and bottom left and bottom right. Edit menu and paste x 3.drag to the top right / bottom left / bottom right
View menu and new guide layout and 2 x 2. The guides are useful to align them. Now flip them. Top right and edit menu and transform and flip horizontal. Bottom left i and bottom right and the transform command and flip vertical. Bottom right and edit menu and transform and flip horizontal
OK, you should now have the tile design. If you see any kinds of seams (they should be minimal but it does depend on the source material) then you can always blur the central seams or use the smudge tool to smudge them slightly to make them less obvious. You can also apply any number of brush edits in the center of the design to create unique artwork.
The tile you have now will be seamless in that the edge pixels will match. You can, if you wish, repeat the entire process with the current tile. A really large tile means that you can add all kinds of manipulation to the inner part of the tile without affecting the seams. Flatten. Edit menu and define command
You can now use the preset in a variety of areas such as fill layers as well as via the fill command and also via the layer effects and also as textures for brushes etc.
You can use the presets (with photos etc) as a great way of creating a basic contact sheet. Add a border around an entire picture by copying and pasting and filling the background with white and then reducing the size of the layer and then flattening and then defining that. You can then use that design with fill layers and scaling of 25% etc to create all kinds of contact sheets from a sing;e photo.
A new feature that is very useful for creating tile designs in the application of preview which can be found in the view menu. You can then re-size, rotate etc (and probably a good idea is to convert it into a smart object) and see the changes made and the tiles updated.