Over the past decade, a large number of browser based simulations for astronomy education were developed using Flash and Java. Simulations have become a staple of many astronomy educators, who have used them to engage students in reasoning about topics previously accessible only to those with advanced mathematics and physics skills. Unfortunately, Flash and Java are rapidly becoming unusable to general education populations in grade schools and colleges due to increased computer security restrictions and non-implementation on smartphones and tablets. Here, we present early efforts by the Foothill AstroSims project to reimplement existing simulations in a framework compatible with modern browsers on computers, smartphones, and tablets. We also present new simulations addressing topics previously unaddressed in freely accessible general-education level simulations (such as dark matter, cosmological redshift, and gravitational lensing).