I have an atrix Motorola and I tried to load the "rider x" app (memory problem) I have a Motorola Atrix and have most all my apps loaded on the sd card.  Seems like I can not get "Rider X" app to work.  It loads but then won't open.  I uninstalled and reloaded.  Sometime I get the message - The location Google Play Store (process com.android.vending) has stopped unexpectedly.  Please try again.  How can I get more internal memory or whatever it is that I need to do?  Thanks
It is probably too old or too new for your phone. If you did not have enough space it would tell you insufficient storage when installing.