Creating a number counter that counts in increments of .05 in After Effects.

This is relatively easy to do with an expression on a text layer's Source Text property. Use the existing timeToFrames() method and divide by 2:

timeToFrames(t = time + thisComp.displayStartTime, fps = 1.0 / thisComp.frameDuration, isDuration = false)/2;

But if you don't want it to trim the decimal place off of integer values, use the toFixed() method.

halfFrames = (timeToFrames(t = time + thisComp.displayStartTime, fps = 1.0 / thisComp.frameDuration, isDuration = false))/2;

halfFrames.toFixed(1);

Just for kicks, I expanded a version that pads leading zeros for up to three pre-decimal digits:

halfFrames = (timeToFrames(t = time + thisComp.displayStartTime, fps = 1.0 / thisComp.frameDuration, isDuration = false))/2;

if (halfFrames >= 10 && halfFrames < 100) {

halfFrames = "0" + halfFrames.toFixed(1);

}

else if (halfFrames >= 0 && halfFrames < 10) {

halfFrames = "00" + halfFrames.toFixed(1);

}

else {

halfFrames.toFixed(1);

}