Add a needs-more-testers note to Android and iOS guides.

doc/Android.md

@@ -10,6 +10,10 @@ There are also rough edges, which will hopefully get polished over time. Most of
 
 This guide assumes you already have installed Cargo and Android Studio (but not that you used both together).
 
+Finally: These guidelines are correct as far as we know, but they haven't
+been tested by many people. If you find any problems in them, please let us
+know!
+
 ## Installing the requirements
 
 First you'll need to install targets so Rust knows how to compile to Android.

doc/iOS.md

@@ -10,6 +10,10 @@ This guide assumes you already have installed Cargo and XCode (but not that you
 
 Apple requires to have MacOS installed to develop iOS apps, this guide won't work for Linux, Windows or other BSDs.
 
+Finally: These guidelines are correct as far as we know, but they haven't
+been tested by many people. If you find any problems in them, please let us
+know!
+
 ## Installing the requiremments
 
 First install targets so Rust know how to compile to iOS