user4592: I don't have many friends to play chess with that are at my skill level so many times I am forced to play against the computer. It seems like the computer plays much differently than a human, or at least, so I hear. 
Is it necessary to play against humans to increase your ability or can playing against the computer yield the same result?

user12282: Playing winning positions vs chess engine is a very useful training. Try it out.

user17828: I consider playing a sparring game with a chess software as  beneficial for a player to enhance his/her playing and analytical skill. I placed 2nd in a chess tournament by merely playing weak Chessmaster version of alphanumeric Nokia phone 3x a day for 5 months. Prior to that sparring sessions, I reviewed tactical postions to improve my game. Thus, I recommend having a chess app for sparring games before competing in an online or formal chess tournament. You can start practicing from lower level up to higher level depending on your preferred playing strength.

user2607: Since you don't mention your elo rating, I would limit for entry level options:
For Chess engines, I suggest the Chessmaster for PC, has many personalities and can play with different styles/openings, so that adds variety (still can be very strong: >2600 elo in the strongest personalities).
On Android I have played lately this one: https://play.google.com/store/apps/details?id=uk.co.aifactory.chessfree, but there are many others.
Still no matter which engine I try, I feel for a given elo rating, a typical engine plays better tactically than a human of similar rating, but worst positionally/strategically than a human of similar rating.
Chess.com is good, also for email chess I like redhotpawn.com.
Finally, I would also suggest playing Chess solo!
UPDATE:
A couple of other Android apps (based on PC engines): Shredder & Chess Genius, they have tunnable difficulty and play more positional chess.

user1815: Playing against an engine is definitely still good practice for your chess. You can typically scale the strength of the engine to make it harder or easier depending on your level. In my experience it tends to be bit boring since most engines tend to favour particular openings and a fairly aggressive style of play.  To combat this you can tell the engine to play a certain line, but this also takes some of the excitement out since you know in advance what the engine will play.
Aside from engines there are always plenty of online options to find a game. For example chess.com is a free site where you can play against basically any strength player. It also offers live matches as well as correspondence games. You can filter by ELO rating to find games against opponents who would suit your skills. 

4592: <p>I don't have many friends to play chess with that are at my skill level so many times I am forced to play against the computer. It seems like the computer plays much differently than a human, or at least, so I hear. </p>

<p>Is it necessary to play against humans to increase your ability or can playing against the computer yield the same result?</p>
 12282: <p>Playing winning positions vs chess engine is a very useful training. Try it out.</p>
 17828: <p>I consider playing a sparring game with a chess software as  beneficial for a player to enhance his/her playing and analytical skill. I placed 2nd in a chess tournament by merely playing weak Chessmaster version of alphanumeric Nokia phone 3x a day for 5 months. Prior to that sparring sessions, I reviewed tactical postions to improve my game. Thus, I recommend having a chess app for sparring games before competing in an online or formal chess tournament. You can start practicing from lower level up to higher level depending on your preferred playing strength.</p>
 2607: <p>Since you don't mention your elo rating, I would limit for entry level options:</p>

<p>For Chess engines, I suggest the Chessmaster for PC, has many personalities and can play with different styles/openings, so that adds variety (still can be very strong: >2600 elo in the strongest personalities).</p>

<p>On Android I have played lately this one: <a href="https://play.google.com/store/apps/details?id=uk.co.aifactory.chessfree" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=uk.co.aifactory.chessfree</a>, but there are many others.</p>

<p>Still no matter which engine I try, I feel for a given elo rating, a typical engine plays better tactically than a human of similar rating, but worst positionally/strategically than a human of similar rating.</p>

<p>Chess.com is good, also for email chess I like redhotpawn.com.</p>

<p>Finally, I would also suggest playing Chess solo!</p>

<p>UPDATE:
A couple of other Android apps (based on PC engines): Shredder &amp; Chess Genius, they have tunnable difficulty and play more positional chess.</p>
 1815: <p>Playing against an engine is definitely still good practice for your chess. You can typically scale the strength of the engine to make it harder or easier depending on your level. In my experience it tends to be bit boring since most engines tend to favour particular openings and a fairly aggressive style of play.  To combat this you can tell the engine to play a certain line, but this also takes some of the excitement out since you know in advance what the engine will play.</p>

<p>Aside from engines there are always plenty of online options to find a game. For example chess.com is a free site where you can play against basically any strength player. It also offers live matches as well as correspondence games. You can filter by ELO rating to find games against opponents who would suit your skills. </p>
