[app] convert the existing apps to the app modules, add new shell app to
contain the console
diff --git a/app/stringtests/string_tests.c b/app/stringtests/string_tests.c
index fcb1e1b..69bdbbe 100644
--- a/app/stringtests/string_tests.c
+++ b/app/stringtests/string_tests.c
@@ -23,6 +23,7 @@
 #include <debug.h>
 #include <string.h>
 #include <malloc.h>
+#include <app.h>
 #include <platform.h>
 #include <kernel/thread.h>
 
@@ -243,3 +244,8 @@
 
 #endif
 
+APP_START(stringtests)
+	.entry = 0,
+	.flags = 0,
+APP_END
+