&gt; What&#x27;s the threat model there?<p>* It annoys me as a consumer.<p>* It reeks of incomptency ( yeah, go and disable that security check that looks like it is there to prevent malicious software to be installed on your device, yeah, yeah, that one ).<p>* It is a convoluted process.<p>* It leaves my device vulnerable. Let&#x27;s not speculate (like you did apparently) but copy and paste from their own source:<p><a href="https:&#x2F;&#x2F;www.amazon.com&#x2F;gp&#x2F;feature.html?ie=UTF8&amp;docId=1003016361&amp;ref_=mas_surl_undrgrnd" rel="nofollow">https:&#x2F;&#x2F;www.amazon.com&#x2F;gp&#x2F;feature.html?ie=UTF8&amp;docId=1003016...</a><p>---<p>Update Phone Settings<p><pre><code>    Go to your phone Settings page
    Tap Security or Applications (varies with device)
    Check the Unknown Sources box
    Confirm with OK
</code></pre>
Step 2
Go to Downloads<p><pre><code>    Open Downloads on your device by going to My Files or Files
    Tap on the Amazon App file (Amazon_App.apk)
    Tap Install when prompted
</code></pre>
Step 3
Launch Underground App<p><pre><code>    Tap Open to launch the Amazon Underground App
    Use the Menu on the left and select Apps &amp; Games
</code></pre>
---<p>Yeah, I don&#x27;t see anything about the &quot;untick the checkbox again&quot; part.