user20719: Knowing nothing but the rules of chess, I'd like to start learning a bit more. Some kind of tutorial app for my Android smartphone would be perfect as I can use it anywhere. The app should give theoretical explanations of basic concepts and thinking patterns (like controlling the center, pawn structure etc.) and preferably mix in a lot of example positions to solve. Free would be great, but I also would't have a problem with paying up to 10€ if it's worth it. Any suggestions?

user25986: I am chess coach. I can recommend Max Chess: https://play.google.com/store/apps/details?id=dim.maxym.mychess
It's very good for beginners. It has very simple interface and few game modes:

In section "Rules of chess" you can play chess against very weak opponent and using unlimited hints from your virtual coach.
In section "Play vs computer" first levels are very easy.
In section "Solve puzzles" you can choose "Easy" puzzles. Most of them is one move puzzles.
In section "Practice" there are many chess endgames for beginners: checkmate using two rooks, checkmate using one queen and etc.


user3456: Free online course full of interactive puzzles https://szachydzieciom.pl/?lang=en
Especially, the Basic Rules Section.

user20727: Why waste your money when you've got free video repository like Youtube.
Watch this video, i think this is perhaps the best video i've ever come across to learn chess.
Some applications on playstore will definitely come handy:

https://play.google.com/store/apps/details?id=com.chess&hl=en
https://play.google.com/store/apps/details?id=com.chessking.android.learn.ctforbeginners&hl=en
https://play.google.com/store/apps/details?id=uk.co.aifactory.chessfree&hl=en

There are many options on playstore but this three were one of the best options.

user12554: As for anything, just try YouTube app: I find this series of videos by Chess network particularly good.
https://m.youtube.com/playlist?list=PLQsLDm9Rq9bHKEBnElquF8GuWkI1EJ8Zp

user-1: I play at Lichess and I also recommend it, but another good free app I use for tactics exercises is ChessTempo. 
It is just my preference. I find the collection of problems better. Lichess exercises are taken from blitz games analyzed by Stockfish. They are fine and free, but sometimes the selection they do with code is not accurate for a human.
The advantage Lichess has is when you do an exercise you can check the engine. This is useful to realize why the line you played fails. At ChessTempo this is not possible, but on messages you can read from other users why the solution and not any other alternative works. 
I also use ChessTempo for my correspondence games, where you are allowed to  check a database, to chose my moves in the opening.

user18963: I would suggest LiChess. It is free (of charge and ads) and it has a website + android app. You can practice vs other opponents, solve tactic puzzles. They also have a learning section, where you can learn about simple strategic concepts.

20719: <p>Knowing nothing but the rules of chess, I'd like to start learning a bit more. Some kind of tutorial app for my Android smartphone would be perfect as I can use it anywhere. The app should give <strong>theoretical explanations</strong> of basic concepts and thinking patterns (like controlling the center, pawn structure etc.) and preferably mix in a lot of <strong>example positions to solve.</strong> Free would be great, but I also would't have a problem with paying up to 10€ if it's worth it. Any suggestions?</p>
 25986: <p>I am chess coach. I can recommend Max Chess: <a href="https://play.google.com/store/apps/details?id=dim.maxym.mychess" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=dim.maxym.mychess</a></p>
<p>It's very good for beginners. It has very simple interface and few game modes:</p>
<ol>
<li>In section &quot;Rules of chess&quot; you can play chess against very weak opponent and using unlimited hints from your virtual coach.</li>
<li>In section &quot;Play vs computer&quot; first levels are very easy.</li>
<li>In section &quot;Solve puzzles&quot; you can choose &quot;Easy&quot; puzzles. Most of them is one move puzzles.</li>
<li>In section &quot;Practice&quot; there are many chess endgames for beginners: checkmate using two rooks, checkmate using one queen and etc.</li>
</ol>
 3456: <p>Free online course full of interactive puzzles <a href="https://szachydzieciom.pl/?lang=en" rel="nofollow noreferrer">https://szachydzieciom.pl/?lang=en</a></p>

<p>Especially, the <a href="https://szachydzieciom.pl/?page_id=61627" rel="nofollow noreferrer">Basic Rules Section</a>.</p>
 20727: <p>Why waste your money when you've got free video repository like Youtube.</p>

<p>Watch this <a href="https://www.youtube.com/watch?v=NAIQyoPcjNM" rel="nofollow noreferrer">video</a>, i think this is perhaps the best video i've ever come across to learn chess.</p>

<p>Some applications on playstore will definitely come handy:</p>

<ol>
<li><a href="https://play.google.com/store/apps/details?id=com.chess&amp;hl=en" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=com.chess&amp;hl=en</a></li>
<li><a href="https://play.google.com/store/apps/details?id=com.chessking.android.learn.ctforbeginners&amp;hl=en" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=com.chessking.android.learn.ctforbeginners&amp;hl=en</a></li>
<li><a href="https://play.google.com/store/apps/details?id=uk.co.aifactory.chessfree&amp;hl=en" rel="nofollow noreferrer">https://play.google.com/store/apps/details?id=uk.co.aifactory.chessfree&amp;hl=en</a></li>
</ol>

<p>There are many options on playstore but this three were one of the best options.</p>
 12554: <p>As for anything, just try YouTube app: I find this series of videos by Chess network particularly good.</p>

<p><a href="https://m.youtube.com/playlist?list=PLQsLDm9Rq9bHKEBnElquF8GuWkI1EJ8Zp" rel="nofollow noreferrer">https://m.youtube.com/playlist?list=PLQsLDm9Rq9bHKEBnElquF8GuWkI1EJ8Zp</a></p>
 -1: <p>I play at Lichess and I also recommend it, but another good free app I use for tactics exercises is <a href="https://play.google.com/store/apps/details?id=com.chesstempo.mobile&amp;hl=es" rel="nofollow noreferrer">ChessTempo</a>. </p>

<p>It is just my preference. I find the collection of problems better. Lichess exercises are taken from blitz games analyzed by Stockfish. They are fine and free, but sometimes the selection they do with code is not accurate for a human.</p>

<p>The advantage Lichess has is when you do an exercise you can check the engine. This is useful to realize why the line you played fails. At ChessTempo this is not possible, but on messages you can read from other users why the solution and not any other alternative works. </p>

<p>I also use ChessTempo for my correspondence games, where you are allowed to  check a database, to chose my moves in the opening.</p>
 18963: <p>I would suggest LiChess. It is free (of charge and ads) and it has a website + android app. You can practice vs other opponents, solve tactic puzzles. They also have a learning section, where you can learn about simple strategic concepts.</p>
