Installation/uninstallation of apps I noticed that when I install and uninstall applications slow down the phone and it is necessary to restart to restore normal function of the phone. Is it a case like a computer's, after installation should be restarted, and how Android resolves this case?!
Normaly it shouldn't restarted. 
If you uninstall an app, it only deletes the apk from the folder /data/app and the app data from the folder /data/data.

Nothing special or magic.