What apps (software) do I need to make my own app cheap?

What apps (software) do I need to make my own app cheap?

appinventor.org is perhaps one of the most popular.  andromo.com is another that crossed my radar again recently.

See also my quick and dirty webpages:

• 100 Best App Building Tools | Meta-Guide.com
• 100 Best AppInventor Videos | Meta-Guide.com