user799: The below puzzle White to mate in two moves. I tried all combinations. I can't figure it out how to solve this? I am starting to think this as a bug in my mobile application which is showing wrong information that it can be solved in just two moves. 
[FEN "2K3Bn/B/3pp1N/1p1P3R/4k/R5q/N1P3Pp/7Q w - - 0 1"]


user2429: To be fair, I tried solving this manually. 
Qb1 works. 
Basic idea - We see that the Black king cannot move. All that is needed is to give it a check. But where to give it a check from? The Black queen guards many key squares like h4, e3, c3, e1. Thus, White should try to find other squares. Qb1 threatens mate with Qb4+. 
This is what I calculated - 
1...exd5 2. Bxd5#
1...e5 2. Qb4#
1...b4 2. Qxb4#
1...h1=Q 2. Qb4#
1...Qxa3 2. c3!#
1...Qe1 2. Qxe1#
1...Qe3 2. Rxe3#
1...Qb3 2. cxb3#
1...Nxg6 2. Qb4#

I also confirmed with a computer that Qb1 is correct. 

799: <p>The below puzzle <strong>White to mate in two moves</strong>. I tried all combinations. I can't figure it out how to solve this? I am starting to think this as a bug in my mobile application which is showing wrong information that it can be solved in just two moves. </p>

<pre><code>[FEN "2K3Bn/B/3pp1N/1p1P3R/4k/R5q/N1P3Pp/7Q w - - 0 1"]
</code></pre>
 2429: <p>To be fair, I tried solving this manually. </p>

<p>Qb1 works. </p>

<p>Basic idea - We see that the Black king cannot move. All that is needed is to give it a check. But where to give it a check from? The Black queen guards many key squares like h4, e3, c3, e1. Thus, White should try to find other squares. Qb1 threatens mate with Qb4+. </p>

<p>This is what I calculated - </p>

<pre><code>1...exd5 2. Bxd5#
1...e5 2. Qb4#
1...b4 2. Qxb4#
1...h1=Q 2. Qb4#
1...Qxa3 2. c3!#
1...Qe1 2. Qxe1#
1...Qe3 2. Rxe3#
1...Qb3 2. cxb3#
1...Nxg6 2. Qb4#
</code></pre>

<p>I also confirmed with a computer that Qb1 is correct. </p>
