It seems like people in general aren’t very fond of grid based level design but I’m crazy about it for a number of reasons that I wont get into right now. If your going to lay out tiles it helps to have an editor rather then needing to place them manually in a text based environment. That’s where mappy comes in. Its a great free and open source (it was made for windows but apparently already compiles fine in Linux) tile map editor. Its not exactly fancy but its totally functional. Its what I used to make the level used in the zombie game and I’m happy with how it worked out.
GLUEit does one simple task but it does it well if and you should need that task accomplished its a massive time saver. It merges a series of images together into one larger image depicting the sequence. Definitely beats stitching images together one by one in photoshop. It thankfully even works with PNG files and wont mess up there transparency.