e.g. in the reaction editor the bond will appear briefly and then disappear.

Seen on Chrome on Android.

On Firefox on Windows on a laptop, the framerate drops to 30 after a few seconds, and even lower if the laptop is not plugged in. This is to save battery. Other browsers dont have this feature. Android doesn't seem to do this.

Whatever the cause, Living Physics should cope - by running the simulation at a constant speed whatever the framerate. Currently the atoms slow down when the framerate drops.

This allows for an over-easy solution: break the chain, separate the colors, remake the chain.

Add a check that the chain doesn't get broken.

Wrong initialized atoms, no way to solve?

y2-y1 -> y3+y4
y3+y3 -> y1-y1
y4+y4 -> y1-y1

This is not the intended sort of solution.

Thanks to Måns Grebäck for pointing this out. (In 2012.)

Add a check that the loop hasn't been broken. Maybe put stuff inside. One atom to go in each daughter cell?

After I add a reaction on level 2 it looks like this:

I can't find a way to close that screen - I guess the button for it is off the edge of the screen?

Currently the default view on mobile web is like this:

which makes touch interaction difficult. Better would be to occupy the whole window:

(thanks to @danbri)

Not easy to reproduce but I've seen cases where a set of reactions has been saved (and is visible in the localStorage in the browser) but only one is loaded for that challenge. This is annoying for the user because it means their work is lost.

(This is a bit ironic, since the code was written for Processing's Android which only had touch.)

For now, you have to use it on desktop with a mouse, and use the mouse as if it is your finger - dragging down to scroll text.

To fix, use touchStart etc.: http://www.bradchen.com/blog/2011/04/processing-js-touch-events

Maybe just temporary - runs until the challenge is passed or the user hits a button or drags.