arXiv.org -- open access to over 800 000 e-prints
Score: 51
Created: Dec 6, 2013 at 12:09
Clicks per day: 0.27 (1,022 total)
Chemistry Stack Exchange
Score: 22
Created: Dec 6, 2013 at 12:11
Clicks per day: 0.26 (970 total)
Space Exploration Stack Exchange
Score: 18
Created: Dec 6, 2013 at 12:14
Clicks per day: 0.36 (1,369 total)
writeLaTeX.com - great for explaining physics, and works on your iPad too!
Score: 16
Created: Dec 6, 2013 at 16:05
Clicks per day: 0.23 (879 total)
Try Sage open-source mathematical software system
Score: 19
Created: Dec 6, 2013 at 16:07
Clicks per day: 0.25 (939 total)
Detexify2 - LaTeX symbol classifier
Score: 42
Created: Dec 6, 2013 at 16:16
Clicks per day: 0.69 (2,628 total)
Free online collaborative $\LaTeX$ editor
Score: 13
Created: Dec 6, 2013 at 16:17
Clicks per day: 0.36 (1,374 total)
Tagline to show on mouseover
Score: 21
Created: Dec 6, 2013 at 16:58
Clicks per day: 0.32 (1,202 total)
MIT's Open Courseware
Score: 38
Created: Dec 6, 2013 at 17:00
Clicks per day: 0.46 (1,723 total)
Khan|Academy
Score: 15
Created: Dec 6, 2013 at 17:12
Clicks per day: 0.25 (949 total)
Digital Library of Mathematical Functions
Score: 22
Created: Dec 6, 2013 at 17:21
Clicks per day: 0.74 (2,808 total)
Space Exploration Stack Exchange
Score: 22
Created: Dec 6, 2013 at 17:24
Clicks per day: 0.78 (2,963 total)
Astronomy Stack Exchange
Score: 16
Created: Dec 10, 2013 at 15:39
Clicks per day: 0.2 (772 total)

Score: 20
Created: Dec 10, 2013 at 20:27
Clicks per day: 0.62 (2,327 total)
arXiv.org: the biggest open-access e-print repository for maths and physics
Score: 18
Created: Dec 11, 2013 at 14:20
Clicks per day: 0.15 (565 total)
A beautiful, free online graphing calculator
Score: 14
Created: Jan 17, 2014 at 10:36
Clicks per day: 0.26 (973 total)
Zotero reference manager: free and open source
Score: 12
Created: Jan 20, 2014 at 17:58
Clicks per day: 0.14 (505 total)
LaTeX Search
Score: 15
Created: Feb 27, 2014 at 11:43
Clicks per day: 0.24 (883 total)
Tagline to show on mouseover
Score: 9
Created: Mar 1, 2014 at 20:00
Clicks per day: 0.23 (842 total)
Community Promotion Ads are proposed and voted on by the Physics SE community
Score: 31
Created: Mar 2, 2014 at 0:52
Clicks per day: 0.18 (680 total)

Score: 26
Created: Mar 8, 2014 at 22:18
Clicks per day: 0.29 (1,053 total)
PhysicsOverflow: a graduate-level upward physics site
Score: 14
Created: May 10, 2014 at 10:52
Clicks per day: 0.37 (1,331 total)
SciRate
Score: 9
Created: Jul 20, 2014 at 14:55
Clicks per day: 0.08 (272 total)
arXiv Analytics: specialized web portal dedicated to reading & discussing arXiv eprints
Score: 6
Created: Sep 12, 2014 at 15:52
Clicks per day: 0.08 (277 total)
The Fun Physics
Score: 11
Created: Oct 11, 2014 at 2:47
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For the geeks interested in fun science questions and answers.
Score: 6
Created: Nov 3, 2014 at 10:39
Clicks per day: 0.04 (134 total)