I could be wrong but these are what I know:
In Android programming, you cannot use the common visual components (TButton, TEdit, etc). You have to choose
LAMW or
Custom Drawn Interface or to use other options, read more here:
http://forum.lazarus.freepascal.org/index.php/topic,38777.msg264428.html#msg264428You can use LAMW without installing Laz4Android, but using Laz4Android is easier. Because Laz4Android already prepared the cross compiler and installed Custom Drawn Interface for you. But you can combine Laz4Android + LAMW if you want.
Custom Drawn Interface has some issue with Android 7 and above, as far as I know the issue hasn't fixed yet.
Last time I use Laz4Android, it can't run on Linux.
If you choose not to use Laz4Android, the manually preparation is complicated. You have to download the Android SDK, NDK and several tools, prepare the cross compiler and configure them properly. For Linux users, I wrote a tutorial here:
http://forum.lazarus.freepascal.org/index.php/topic,42527.0.htmlHave fun!