One virtual world app is pocket legends. It's like world of Warcraft but for touch.onother world is freerealms runescape callofduty clubpenguin wizard101 zwinky toontown
Pop tropics is a good virtual world
Apple has a huge assortment of apps, primarily for gaming. However, they have some very good apps that can be used for education, such as Lumosity and Blackboard, which is a gateway for college students to get into the online application for their classes.
The National Journey Planner has apps that are available for Android and Apple Smartphones. These apps may be downloaded for free.
Apple is too good for Android to take their apps directly. Their display would look weird on their devices anyway.
poptropica
Probably the top ten virtual world games!SmallworldsBinweevilsclub penguinmoshi monstersWebkinzPandandamydinosStardollIMVUPoptropica
ONVERSE!it is the best virtual world sign up here
Neopets or fantage
Onverse.com Well for age 13 and up, there is no better free virtual world than Onverse!
Xivio.com is great! Its a 3D no download free virtual world!!!
unless your ipod is jailbroken you wont be able to download app from anywhere out of the apple app store