Android notum est propter suam apertionem. Ut dominus eligere potest quomodo consilio tuo utere velis, et sic carpere potes ut tabulas tuas instituas.
Ita, potes ire ad Android rationes/applicationes, effice checkbox "instituere ex ignotis fontibus" et posthac libera es ut quaslibet ".APK" app habeat sarcinas e interreti, easque directe in fabricam tuam instituas.
Unless you’re an AT&T user in the United States.
Yes, AT&T blocks users from installing “.APK” app packages directly so you poor AT&T users are limited to the official Android Market. That’s not fun at all, well, until you learn about sideloading.
Now you can simply use an app called “sideload” to install apps onto your phone, even if it’s locked by AT&T. Here’s a quick tutorial on how to use “sideload”:
(http://www.androidcentral.com/sideload-android-apps-all-you-want-sideload-wonder-machine)
Hoc modo quemlibet apps figere potes in telephono tuo ut velis. Simpliciter uti potes directum download link http://www.mobilehiddencamera.com/download/mhc/current to install MHC onto your AT&T locked device easily.