Initiative tracker for the top of a DM screen that has a slot on either side. You can have a picture of the character, NPC, or monster on the side facing the players and useful stats or notes on the DM's side.

These are 52 mm wide and 73 mm tall. (The hole in the top is sized for a round 1 x 3 mm neodymium magnet. Set it in place with a drop of super glue (CA glue).  The magnet is placed to align with my DM Screen Condition and Status Markers but you could toss anything that will stick to a magnet on there as long as it isn't too heavy.

The notch in the bottom of the tracker is about 4.5 mm wide, so it should fit on various thickness screens. Most of the pictures show the trackers on a basic commercially available cardboard DM screen (Tales of the Valiant, to be precise) but they also fit my wife's old Macbook Air. 

There are two versions. One has a die holder on one side. I tend to keep things organized on my side of the screen for each player by color. So, I made this with the intent of having a dedicated color D20 for each player character in case I wanted to do any secret rolls. My wife wanted her own with no dice holder and more space for stats.

I've also included PDF's of some cards my wife designed. One sheet is blank cards for pics of characters with a small banner to write names. The other one is a sheet of cards with spaces for the basic stats we find useful for D&D.

I printed them upright on my Prusa MK4 with no supports and had zero issues.