Sumdog is an online games-based learning service to help students practice their numeracy and literacy. Designed to supplement teaching, it motivates students by adapting to each child’s level. Some of the math games can be played freely, more become available by signing up for a free account. School and family subscriptions are also available.
Sumdog works both on internet browsers and apps on iOS, Android and Kindle.
GeoGebra is an interactive mathematics software program for the teaching of mathematics and science from primary school through to university. Graphs, animations, simulations and more can be constructed with points, vectors, segments, lines, polygons, conic sections, inequalities, implicit polynomials and functions. All of these can be changed dynamically afterwards too, adding a fun element of play to the tool. Particularly when creations are shared for other students and classrooms to enjoy.
GeoGebra is available on multiple platforms with its desktop applications for Windows, Mac OS and Linux, with its tablet apps for Android, iPad and Windows. Additionally it’s an Open Educational Resource as its source code is licensed under the GNU General Public License (Wikipedia link), and all other non-software components are under Creative Commons BY-NC-SA.