Free App to Create 3D Sculptures - 123D Sculpt+

Autodesk's 123D Sculpt+ is absolutely the top App for creating 3D models on your Android tablet or iPad. Starting from stick figures, you can sculpt the details, paint the textures and pose your models. You can export your creations to OBJ files for further editing and can share them to the community easily.

This free App is available at Google Play and the App Store. What's more, according to the 123D FAQ, your creation can even be used for commercial purposes freely if you share it to the 123D Gallery!

Get the App at: http://www.123dapp.com/sculptplus

Update on 2015/7/3: The windows version of sculptplus has finally been released! See the official blog for details: http://blog.123dapp.com/2015/06/123d-captures-windows-phones-and-tablets

Update on 2017/5/16: Sad news, 123dapp was closed! See announcements here:
http://web.archive.org/web/20170406144218/http://blog.123dapp.com/2016/12/important-news-about-the-next-chapter
http://web.archive.org/web/20161223192148/https://support.tinkercad.com/hc/en-us/articles/115000144307-Can-I-still-use-the-apps- 
The new successor by Autodesk is web based app https://www.tinkercad.com/, but it seems that it has no sculpting functionality.
The 123D Sculpt (with limited functions) can still be downloaded at:
https://www.microsoft.com/en-us/store/p/123d-sculpt/9nblggh39h05 (Windows)
https://apkpure.com/123d-sculpt/com.autodesk.Sculpt (Android)

KOReader - Turn Your Android Phone and Tablet into a Kindle-like E-reader

KOReader is an open source document viewer, originally created for Kindle e-ink readers. It currently runs on Kindle 5 (Touch), Kindle Paperwhite, Kobo and Android (2.3+) devices.

The most important feature of this app as a pdf reader that many other apps (including Adobe's own PDF Reader for Android) don't have, is text reflow for scanned documents and scientific documents with lots of mathematical formulas, thanks to its built-in K2pdfopt support. What's more, since it is originally designed for Kindle e-ink reader, the app has a very similar look and feel as the Kindle e-ink user interface, which is very clean and elegant. However, first time users may not be used to this Kindle-like interface and touch. For example, at first I thought I need to scroll down from the top of the screen to open reader's setting menus, which is of course a conflict with the default gesture input for opening the Android message center. Then I realized that a single tap at the top center of the screen is the right way to open the setting (while the typical back and menu buttons of an Android phone actually do nothing with the app). But if you have some experience with the Kindle e-reader, it is very natural and easy for you to get started with the app.

This free app can be download at:
https://github.com/koreader/koreader/wiki/Download
(Including ".apk" version for Android phones and tablets, as well as the Kindle and Kobo e-ink reader version.)

Links:
http://www.mobileread.com/forums/showthread.php?t=209276
https://github.com/koreader/koreader/ (Source Code: AGPL)

The Internet Archive's MS-DOS showcase - Run Old DOS Programs and Play Old DOS Games in Your Browser

Based on the open source DOS emulator DOSBox's Emscripten port,the Internet Archive collected many old DOS programs and games that can run directly in your browser:
https://archive.org/details/softwarelibrary_msdos_games

The collection include many famous old DOS games, such as 4D Prince of Persia, Bruce Lee, Wolfenstein 3D, SimCity and Tyrian.

See also: http://js-dos.com 

Links:
http://ascii.textfiles.com/archives/4487
http://mozakai.blogspot.com/
https://archive.org/details/softwarelibrary_win3 (Windows 3.1 programs run in browser)

The Black Heart - Free Gothic M.U.G.E.N. Fighting Game

Featured in the book "250 indie games you must play" by writer Mike Rose from indiegames.com, "The Black Heart" is a fighting game based on the M.U.G.E.N. engine.It has six playable characters, and were all made by one person (Andrés Borghi) through 7 years of hard work.

If you enjoy pixelated blood, fluid gameplay in Capcom style, combos, tragic and epic music, weird pictoric landscapes and complex storytelling this is the game for you!

Game Download:
http://gamejolt.com/games/action/the-black-heart/14718/
Official Site:
http://www.theblackheart.com.ar/