Check out http://www.mojopac.com when looking for portability and apps running from an external USB. They are now offering a so called Freedom version for free.
Downside: you have to agree to some Anonymous User Data collection
also check forum about what works and what doesn't.
Whilst the Mojopac in itself can get corrupted easily (always have a clean install backup), a lot of apps do run. I put all the GOATD offerings on it that I might just need one day. Also, the games I downloaded here recently all run great.
So, for those that don't mind some data mining ... and don't want to shell out the $ 50 just yet
Pura Vida