title: Lag Android app after some time
body: <p>Well the question is that I have an app with multiple activities. The main activity runs several animations and the problem is that if I run the app and stay in the main activity everything is all right but if I go to another activity (the setting activity, for example) and come back to the main one, after some time the hole app begins to lag.
  Any clue about why is this happenning? May the other activities keep running in background or something like that?
  Thank you all.</p>