Play Commander Keen 1 4 7 and Dreams (Shareware) for free on your android device!

Episode 2 3 5 and 6 can also be played when you copy them to your data directory. You can get Episode 2 3 and 5 on Steam. Keen 6 is harder to get (Ebay might help). Please consider that.

Those app downloads the shareware versions of Commander Keen episode 1 4 and a mod called Keen 7 for you. You can also enable the HQP (High Quality Pack) which enhances music and graphics

About Keen 7:
http://www.shikadi.net/keenwiki/The_Keys_of_Krodacia

Many Keen 12345 and 6 mods are now supported.

Sources can be downloaded from the developers' Site.