I missed the browser part, but ChemDraw is industry standard, proprietary software suite that is quite expensive - think if each program in the adobe creative suite cost as much as the entire package. If anyone is a university student then there is a good chance that you have access to this software, but it is prohibitively expensive otherwise.
Just to expand on your original request, computational chemistry can be very resource intensive. The program features you highlighted appear to be somewhat whimsical or simple, but there can be an immense resource demand in both creating an application to serve such a broad purpose in chemistry along with the environment to run it. Getting that to work as a web app for a lot of cases would probably be pretty difficult.
That being said, the program chemsketch isn't a webapp, but it is a decent alternative to ChemDraw.
we use chemsketch as well it might not be the best looking but its relitivly easy and free. if you are on mac chem doodle i hear works well. here is the link to chemsketch site http://www.acdlabs.com/resources/freeware/chemsketch/
ChemSketch and Accelerys are the two I've used. Not quite as sleek as ChemDraw, but they work just fine.
http://upload.wikimedia.org/wikipedia/commons/a/a9/Amino_Acids.svg
Check out this table, it gives the single-letter codes and structures for the amino acids.
I used ACD ChemSketch to make the peptide bonds and design the final layout of the stencil.
If you're in university, most will have a license for Chemdraw somewhere on their software/chemistry page. Check there first.
I haven't personally used anything except Chemdraw, but I've heard good things about Chemsketch, which has a free version for personal use.
I use ChemSketch. Never used ChemDraw, but I'm pretty sure ChemSketch will generally be worst. Still, it's free.
Also:
> We lost a copy to a terminally ill student
0-100 very fast.
It depends on what the structure is. For some recently discovered metabolite, it's important to state the source of the structural data. However for any image that you re-use, you need to follow proper attribution guidelines. As /u/superhelical stated, the proper action is to re-draw the structure using chemdraw (your university probably has a free license) or other similar program such as ChemSketch.
I don't have anything to add on to what others are saying, other than pictures of the chemical structures, either made yourself (I like chemsketch: http://www.acdlabs.com/resources/freeware/chemsketch/) or referenced from wikipedia, though i don't know the licensing for that. I thought the coloured powders were a bit boring by themselves
If you're taking notes for an upper-level chem course (especially organic chemistry), get ChemSketch or something similar. Makes nice, smooth diagrams, and is free! Copies and pastes right into Word, and probably other programs as well.
See, I don't know much about programming, but I have this program on my computer: http://www.acdlabs.com/resources/freeware/chemsketch/ and basically, it has templates for most functional groups/structures. But overall this program has helped me write synthesis and naming questions that go beyond my textbook. But if this would exceed the functionality of the iPhone, could it be made for the iPad? But seriously, your apps are great!
ACD/ChemSketch is rather solid even in the Freeware version.
If that doesn't work try ISIS/Draw which seems to have been rename to Accelrys Draw
AccelrysDraw (http://accelrys.com/products/informatics/cheminformatics/draw/no-fee.php), ChemSketch (http://www.acdlabs.com/resources/freeware/chemsketch/) and MarvinBeans (http://www.chemaxon.com/products/marvin/marvinsketch/) are free for academic licenses. Those three programs include molecular drawing functions.